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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

The association between physical activity, functional fitness and balance in senior citizens / Volschenk A.

Volschenk, Annegret January 2011 (has links)
During the past decades there has been an increase in longevity. These aging trends have an enormous economic impact and present challenges to policymakers, families, and health care providers to meet the needs of aging individuals. Aging is accompanied with various physiological changes that can limit the elderly’s functional status and their independency. Some of the most noticeable changes occur within the musculoskeletal system, however cardiorespiratory changes, as well as changes in the body composition limits the elderly’s aerobic capacity and therefore increases the risk for cardiovascular and hypokinetic diseases. Moderate physical activity reduces the risk, or prolong the onset of physiological changes and various diseases. Physical activity can also enhance functional fitness amongst the elderly. Functional fitness is having the physiologic capacity to perform normal everyday activities safely and independently without undue fatigue. The aim of this study was to determine the functional fitness as well as static balance and dynamic balance status of senior citizens. Secondly, to determine the association between: physical activity, aerobic endurance and functional fitness and status amongst senior citizens. Thirdly, to determine the association between physical activity status, aerobic endurance and static– and dynamic balance amongst elderly. A once off subject availability study was performed, and 58 senior citizens (32 females and 26 males) between the ages of 65 years and 96 years participated. The physical activity index was determined with the Sharkey and Gaskill Physical activity index questionnaire. Functional fitness was measured using the Rikli and Jones Fullerton’s functional fitness test protocol. The static balance and dynamic balance was tested with the one leg balance eyes closed and functional reach test respectively. Descriptive statistics were used to describe the status of the participants. Two way summary tables were used to categorize the amount of weak test results. Partial correlations were used to determine the association between physical activity, functional fitness and static and dynamic balance. The male participants’ functional fitness status compared well with USA normal ranges, however the functional fitness test scores of the female participants were even lower than the older age group (75 to 79 years) of the USA normal ranges. The results of the frequency distribution indicated that 80.77% and 68.75% of the male and female participants respectively, tested poorly in more than four of the functional fitness tests. Neither the male nor the female participants’ static balance score were adequate, although it does not indicate a fall risk. Aerobic endurance showed to have medium (r = 0.3–0.49) to high (r 0.5) partial correlation with all functional fitness tests for the total group, as well as in the female participants. In the male participants aerobic endurance only showed high correlation (r 0.5) with lower body strength and dynamic balance and agility. Dynamic balance correlated well (r 0.5) with all functional fitness tests as well as aerobic endurance and physical activity index in the female participants, and only showed a medium correlation with agility in the male participants. This study showed alarming percentages of poor test results for both male and female senior citizens and highlights the need for physical activity interventions in old age homes. The correlations between aerobic endurance, as well as dynamic balance and functional fitness tests indicates that even simple interventions such as walking programs could enhance the functional fitness of senior citizens and thereby increase their independency. / Thesis (M.A. (Biokinetics))--North-West University, Potchefstroom Campus, 2011.
22

The effect of an enhanced quality physical education programme on physical activity and fitness among grade 7-learners in Potchefstroom / Haili Tian

Tian, Haili January 2015 (has links)
The low physical activity (PA) levels of children have become a national public health concern in South Africa. Moreover, the quality of Physical Education (PE) in South African schools has been compromised by challenges resulting from the subject’s reintroduction after a long absence from the school curriculum. Up to date no study has investigated the effects of a quality PE programme, within the prescriptions of the South African Curriculum and Assessment Policy Statement (CAPS), on the PA and fitness levels of twelve to thirteen years old South African children. Furthermore, no PA measuring instrument exists that has been validated specifically for South African children of this age group, with which to conduct such a study. The objectives of this study were therefore, firstly, to validate a standardised PA questionnaire for Grade 7 learners in a South African context; secondly, to evaluate the effects of an enhanced quality PE programme presented by well-trained teachers, on the PA levels, and thirdly on the physical and motor fitness of Grade 7 learners in Potchefstroom, South Africa. For the first objective, 108 schoolchildren aged twelve to thirteen years (boys, n=45; girls, n=63) from two primary schools in Potchefstroom participated in this study to validate the Children’s Leisure Activities Study Survey (CLASS) for children in a South African context. Test-retest reliability of the questionnaire was examined with an interval of 3 weeks, while validity was assessed by comparing measurements of the reported minutes in PAs from questionnaire responses with ten physical fitness parameters using the Eurofit test battery. Data analysis included Cronbach’s alpha coefficients, paired t-test and intra-class correlation coefficients (ICC), and Spearman correlation coefficients (r). The results showed substantial internal consistency and significant intra-class correlations estimates for all intensities of PA and sedentary time (ST). Non-significant differences were found in the means of test and retest measurements. Aerobic fitness was significantly correlated with all intensities of PA and ST, and the results of several of the other fitness tests had significant associations with vigorous PA. For the fulfillment of the second and the third objectives, 110 Grade 7 learners (experimental school, n = 40; control schools, n = 70) were studied. The twelve-week PE intervention programme was presented according to the prescriptions of the CAPS which allocates one hour per week to PE, but included 5 quality-enhancing components namely well-trained teachers, homework activities, a reward system, improvised apparatus and the monitoring of activity intensity. Data was collected by means of the validated CLASS questionnaire, anthropometric measurements as well as physical and motor fitness tests, by means of the Eurofit test battery. Data analysis included Kruskal-Wallis and Wilcoxon signed-rank tests, a series of analyses of covariance (ANCOVA), Tukey’s post hoc analysis, and interpreting effect sizes for practical significance. The results showed practically and statistically significant increases in moderate PA, vigorous PA, and total PA as well as decreases in sedentary behaviours. Furthermore, the learners’ data on physical and motor fitness levels showed statistically significant improvements among most of the experimental groups with regard to six of the ten fitness parameters. Based on these results, it can be concluded that the enhanced quality PE programme is effective in improving the PA, physical and motor fitness levels of South African primary school children. Therefore it is recommended that PE programmes in South Africa include the quality-enhancing components used in this intervention programme. Moreover, the modified CLASS questionnaire is a valid and reliable measure of PA among South African Grade 7 schoolchildren. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015
23

The effect of an enhanced quality physical education programme on physical activity and fitness among grade 7-learners in Potchefstroom / Haili Tian

Tian, Haili January 2015 (has links)
The low physical activity (PA) levels of children have become a national public health concern in South Africa. Moreover, the quality of Physical Education (PE) in South African schools has been compromised by challenges resulting from the subject’s reintroduction after a long absence from the school curriculum. Up to date no study has investigated the effects of a quality PE programme, within the prescriptions of the South African Curriculum and Assessment Policy Statement (CAPS), on the PA and fitness levels of twelve to thirteen years old South African children. Furthermore, no PA measuring instrument exists that has been validated specifically for South African children of this age group, with which to conduct such a study. The objectives of this study were therefore, firstly, to validate a standardised PA questionnaire for Grade 7 learners in a South African context; secondly, to evaluate the effects of an enhanced quality PE programme presented by well-trained teachers, on the PA levels, and thirdly on the physical and motor fitness of Grade 7 learners in Potchefstroom, South Africa. For the first objective, 108 schoolchildren aged twelve to thirteen years (boys, n=45; girls, n=63) from two primary schools in Potchefstroom participated in this study to validate the Children’s Leisure Activities Study Survey (CLASS) for children in a South African context. Test-retest reliability of the questionnaire was examined with an interval of 3 weeks, while validity was assessed by comparing measurements of the reported minutes in PAs from questionnaire responses with ten physical fitness parameters using the Eurofit test battery. Data analysis included Cronbach’s alpha coefficients, paired t-test and intra-class correlation coefficients (ICC), and Spearman correlation coefficients (r). The results showed substantial internal consistency and significant intra-class correlations estimates for all intensities of PA and sedentary time (ST). Non-significant differences were found in the means of test and retest measurements. Aerobic fitness was significantly correlated with all intensities of PA and ST, and the results of several of the other fitness tests had significant associations with vigorous PA. For the fulfillment of the second and the third objectives, 110 Grade 7 learners (experimental school, n = 40; control schools, n = 70) were studied. The twelve-week PE intervention programme was presented according to the prescriptions of the CAPS which allocates one hour per week to PE, but included 5 quality-enhancing components namely well-trained teachers, homework activities, a reward system, improvised apparatus and the monitoring of activity intensity. Data was collected by means of the validated CLASS questionnaire, anthropometric measurements as well as physical and motor fitness tests, by means of the Eurofit test battery. Data analysis included Kruskal-Wallis and Wilcoxon signed-rank tests, a series of analyses of covariance (ANCOVA), Tukey’s post hoc analysis, and interpreting effect sizes for practical significance. The results showed practically and statistically significant increases in moderate PA, vigorous PA, and total PA as well as decreases in sedentary behaviours. Furthermore, the learners’ data on physical and motor fitness levels showed statistically significant improvements among most of the experimental groups with regard to six of the ten fitness parameters. Based on these results, it can be concluded that the enhanced quality PE programme is effective in improving the PA, physical and motor fitness levels of South African primary school children. Therefore it is recommended that PE programmes in South Africa include the quality-enhancing components used in this intervention programme. Moreover, the modified CLASS questionnaire is a valid and reliable measure of PA among South African Grade 7 schoolchildren. / PhD (Human Movement Science), North-West University, Potchefstroom Campus, 2015
24

The relationship between leisure-time physical activity and psychological well-being in executive employees of selected African countries / Thendo Maureen Thangavhuelelo

Thangavhuelelo, Thendo Maureen January 2013 (has links)
Participation in leisure-time physical activity (LTPA) is vital to ensure adequate physical work capacity for the demands of daily living and job performance. Due to work demand, most top and middle (executive) managerial employees become physically inactive and experience psychological and other health problems which may lead to hypokinetic diseases and even premature death. The purpose of this study was twofold: to determine leisure-time physical activity and psychological well-being status of executive employees; and to determine the relationship between leisure-time physical activity and psychological well-being status of executive employees in selected African countries. A cross-sectional study design was carried out on a group of 156 (mean age 41.22±10.17) available executive employees from selected African countries. Participants were grouped according to age (≤35 years; 36–46 years and ≥ 46 years). Standardised questionnaires were used to collect the data. Subsequently, total scores were calculated for all variables. Out of 156 participants in the study, 42.9% occupied top level management and 57.1% middle level management positions. When data was analysed according to age groups, 31.4% and 68.6% in the less than 35 years age group were in the top and the middle level management positions respectively. In the age group 36 to 46 years, 47.2% occupied the top level management position and 52.8% occupied the middle level management position. With regard to LTPA, top level managers (71.6%) scored low LTPA compared to the middle level managers (62.9%). In addition, both the top and middle level managers reported bad emotional index (49.3%; 56.2%) and happiness index (41.8%; 37.1%) respectively. Though not significant, LTPA was positively associated with psychological well-being parameters amongst top level managers. The study concluded that both top and middle level managers exhibited low LTPA, and with no participation in high physical activity among top level managers. In addition, more middle level managers reported bad emotional stage than the top level managers, while the top level managers were less happy than the middle level managers. The study therefore recommends urgent strategic intervention programmes for leisure-time physical activity and psychological well-being. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2014
25

The role of attitude and barriers on the implementation of a nutrition intervention in primary school children / Michelle Harris

Harris, Michelle January 2012 (has links)
Background: South Africa is a multicultural, multi-ethnic developing country currently experiencing a unique quadruple burden of disease, of which malnutrition (both over- and under nutrition) is one of them. The increase in childhood obesity within the current South-African health setting is of serious concern, approximately 14% boys and 18% girls currently are overweight and it is estimated that this number will increase to 25% within the next decade. Healthy eating habits and increased physical activity are important components of a healthy lifestyle, and decrease the risk of overweight and obesity. It is also often the corner stone of many lifestyle modification intervention programmes aimed at preventing or decreasing overweight/obesity. Aim: This sub-study was part of a larger intervention study where a nutrition education intervention programme (NEIP) for children in the form of a musical play (based on the South African Food Based Dietary Guidelines [SAFBDG]) was developed to increase nutrition knowledge and thereby also contribute towards healthy lifestyle behaviour. The aim of this sub-study was therefore to explore and describe the attitude of a specific group of primary school children (aged 6-12 years) towards healthy eating, unhealthy eating, and physical activity before and after a NEIP as well as the standard school curriculum. Secondly, it was aimed to identify possible barriers to and motivators for healthy eating, unhealthy eating and physical activity. Methods: Children were randomly selected from the experimental group (n=143) of the main study. Children were selected into one of four focus groups per school (6 children per focus group) from which qualitative data were gathered on children’s attitude and perception towards healthy eating, unhealthy eating, and physical activity. Focus groups were defined by age and gender (boys and girls seperately, grades I-III and grades IVVI seperately), totalling a number of 96 children. A total of 75 children completed this sub-study, 21 children dropped out due to school-related problems or after school activities that clashed with the time slots during which the NEIP was implimented. Quantitative data was gathered with a socio-demographic and physical activity questionnaire, as well as a 3-point hedonic facial expression scale which was used to quantify attitude towards healthy eating, unhealhty eating and physical activity. All data (quantitative and qualitative) were collected at both baseline and end measurements. Results: The main findings of this sub-study were that the attitude of most primary school children towards healthy eating, unhealthy eating or physical activity remained unchanged after a unique NEIP. Five major themes were identified out of focus group discussions namely health awareness, healthy eating, unhealthy eating, physical activity, and consequences of unhealthy eating and sedentary behaviour. Mothers were identified as the main motivator for eating healthy and avoiding unhealthy eating. The taste and smell of food were both either identified as motivators or barriers for healthy eating and unhealthy eating. Older girls associate unhealthy eating with becoming fat while many children associate the combination of unhealthy eating and being sedentary with becoming fat. Most children have a positive attitude towards physical activity and enjoy doing it although the biggest motivator for partaking in physical activity is their parents and not themselves. Conclusion: Even though some children’s attitude did change in the desired direction after the implementation of a unique and fun NEIP, most children’s attitude towards healthy eating, unhealthy eating and physical activity remained unchanged. This might have been due to the measurement tool that was not sensitive enough to detect subtle changes. Various factors that can influence children’s attitude and perceptions towards healthy eating, unhealthy eating and physical activity both positively or negatively were identified. This study is one of only a few that explored and described the ‘true’ motivators of and barriers for children’s attitude towards healthy eating, unhealthy eating and physical activity. Results generated from this sub-study can thus make a valuable contribution to the existing literature available in this specific study field. / Thesis (MSc (Dietetics))--North-West University, Potchefstroom Campus, 2012
26

Cloning and expression of human recombinant isoform a of glycine-N-acyltransferase

Grundling, Daniel Andries January 2012 (has links)
Awareness of detoxification, nowadays known as biotransformation, has become an integral part of our daily lives. It is a modern buzz word that is used to promote anything from health food to enhancement of performance in sports. Another lesser known application for detoxification is as a therapy for alleviating symptoms of inborn errors of metabolism. Detoxification is the process where endogenous and xenobiotic metabolites are transformed to less harmful products, in the liver and kidneys, in two phases. Phase 1 detoxification includes oxidation, hydroxylation, dehydrogenation metabolic reduction and hydrolysis. Phase 2 detoxification uses conjugation reactions to increase hydrophillicty of metabolites for excretion in bile and urine. Glycine N-acyltransferse (GLYAT; EC 2.3.1.13) is one of the amino acid conjugation enzymes. There are two variants of human GLYAT. I focused on the full-length mRNA human GLYAT isoform a, with a long term view of using it as a viable therapeutic enzyme for enhanced detoxification of harmful metabolites. I investigated if it is possible to clone and express a biologically active GLYAT. To achieve this goal I used three expression systems: traditional bacterial expression using the pET system; second generation cold shock bacterial expression using the pCOLDTF expression vector to improve solubility of the recombinant protein; and baculovirus expression in insect cells since therein some form of post translation glycosylation of the recombinant protein can occur which might improve solubility and ensure biological activity. The recombinant GLYAT expressed well in all three expression systems but was aggregated and no enzyme activity could be detected. A denature and renature system was also used to collect aggregated recombinant GLYAT and used to try to refold the recombinant protein in appropriate refolding buffers to improve solubility and obtain biological activity. The solubility of the recombinant GLYAT was improved but it remained biologically inactive. / Thesis (MSc (Biochemistry))--North-West University, Potchefstroom Campus, 2013.
27

The relationships between leisure-time physical activity and health related parameters in executive employees of selected African countries / M. Mohlala.

Mohlala, Meriam January 2012 (has links)
Leisure-time physical inactivity is a global public health concern affecting all people in different walks of life, including employees. This inactivity is associated with chronic diseases of lifestyle as well as low work capacity. The purpose of this study was two-fold: to determine leisure-time physical activity (LTPAI), coronary risk- (CRI), health status (HSI) and lifestyle (LSI) indexes of some executive employees in selected African countries; and to determine the effect of leisure-time physical activity (LTPA) on the coronary risk-, health status- and lifestyle- indexes of some executive employees in selected African countries.A cross-sectional study design was followed on a group of 156 (mean age 41.22±10.17) executive employees. Participants were grouped according to age (<35 years; 36–46 years and > 46 years). Standardized questionnaires were used to collect data. Out of 156 participants in the study, 43% occupied top level management and 57% middle level management positions. When data were analyzed according to age groups, 31% and 69% in the less than 35 years age group were in the top and the middle level management, respectively. In the age group 36 to 46 years of age, 47% were in the top level of management and 52.8% middle level management. With regard to LTPA, top level managers (71.6%) scored low LTPA as compared to middle level managers (62.9%). Top level managers scored higher percentages (14.9%) for developing the risk of coronary heart disease. The results show a negative effect of physical activity on selected health parameters, with significant negative relationships between low LTPA and daily lifestyle index (r= -0.52; p=0.01), and moderate LTPA and daily lifestyle index (r= -0.71; p<0.001) for middle managers. It can be concluded that both top and middle level managers exhibited low LTPA and high risk for developing coronary heart disease. It was apparent that the managers in low LTPA are prone to bad stages of life style, health status and coronary risk- indexes compared to the ones with moderate and high LTPA. Additionally, low and moderate LTPA inversely affected selected health parameters of executive employees. No significant association was found for high LTPA with selected health parameters. The study therefore recommends a strategic intervention programme geared towards improving the present state of affairs among the managers in the corporate environment. / Thesis (MA (Biokinetics))--North-West University, Potchefstroom Campus, 2013.
28

Physical activity related to health components and medical costs in employees of a financial institution / Madelein Smit.

Smit, Madelein January 2012 (has links)
Physical activity has several advantages for health. The first objective of this research was to determine the relationship between physical activity and selected physical and psychological health components. The physical components include: diabetes risk, obesity, cholesterol and cardiovascular disease. The psychological health components include stress and depression. Secondly, this research aimed to determine the relationship between physical activity and medical costs. Medical costs were divided into pharmaceutical, general practitioners and hospital claims. A total of 9 860 employees of the same financial institution in South Africa, between the ages 18 and 64 (x̄ = 35.3 ± 18.6 years), participated in the study and participation was voluntary. No differentiation was made between race groups. The assessment of selected health risk factors and physical activity was done by using the Health Risk Assessment (HRA) methodology developed by the company, Monitored Health Risk (MHM). Assessment included a physical activity, diabetes risk and cardiovascular risk questionnaire, BMI and random blood glucose measurements, as well as stress and depression scores. The amount of days absent from work in the past six months was also determined by the questionnaire. Participants was categorised in three groups – low, moderate and high physical activity participation. Medical expenditure data was obtained from Monitored Health Risk Management Pty (Ltd). Hospital, pharmaceutical and general practitioners (GP) claims included all costs occurring during a six month period. The majority of the study group showed low physical activity participation (78.27%). The results also showed that both men and women showed an increased risk for diabetes, and high physical activity levels have a practically and statistically significant effect on the reduction of diabetes risk. In this study all the physical activity groups of both males and females showed an increased average body mass index (BMI) and therefore are considered to be an increased risk according to the classification as stipulated by the study perimeters. The average means for cholesterol in all groups are categorised as low risk. No significant differences are seen between the female groups as well as between the different male groups. The men in the study group showed higher cardiovascular risk than women. There are no statistically significant differences between the women’s groups. However, regarding the male groups, the low physically active male group showed significant differences to the high physical active male group. Thus, in this study it appears that the men participating in high levels of physical activity show the lowest risk for cardiovascular disease and therefore appear to be influenced by physical activity. The majority of the study group is shown to be in the high stress category (55.48%). It seems that work issues (82%), financial problems (74%) and family problems (69%) contribute most to the population’s high stress levels and depression experience. The Physical activity index (PAI) in relation to stress only shows practical significance in moderate and high physical women. The PAI and stress-related index reports statistically (p≤0.05; 0.001) significant and practice significant difference within the population. There was also a statistically significant (p≤0.05) relation between stress and physical activity in relation to days absent. Although high levels of stress and low levels of physical activity are present in the population, the relation become statistically significant in relation with depression. The study group was divided into two groups when the medical cost was examined. One group consisted of those individuals who do not use chronic medication and the other group, those individuals that use chronic medication. The majority of the study group (chronic and nonchronic medication use), show low physical activity participation (average of 78.80%). The results show statistically and practically significant differences between the groups that do not use chronic medication and the groups that use chronic medication. The women that use chronic medication show an increase in pharmaceutical costs with an increase in physical activity. However, when investigating the GP cost of women who use chronic medication, there is only a small difference in GP cost in the different physical activity participation categories. The data shows that men have higher pharmaceutical costs than women in all the physical activity categories. The results also indicate that men who use chronic medication, participating in low levels of physical activity do show higher pharmacy and GP costs. Medical cost associated with hospitalisation of those men whose chronic medications show an average higher medical cost (R231.72 versus R672.71). The women who are on chronic medication show about two and a half times higher hospitalisation cost (R253.97 versus R650.82) and the men an almost four times higher cost (R189.34 versus R721.71). No practically significant difference was found between the groups. The women show an increased incidence of low physical activity participation (82.38%), whereas 68.80% of the men show low physical activity participation. Women who use chronic medication and participate in moderate physical activity show lower hospital costs. The women in this study group that use chronic medication and participate in high levels of physical activity show the highest hospital cost. The men’s profile indicates that medical cost due to hospital claims rise with the higher levels of physical activity. / Thesis (PhD (Human Movement Sciences))--North-West University, Potchefstroom Campus, 2013.
29

The relationship between leisure-time physical activity and psychological well-being in executive employees of selected African countries / Thendo Maureen Thangavhuelelo

Thangavhuelelo, Thendo Maureen January 2013 (has links)
Participation in leisure-time physical activity (LTPA) is vital to ensure adequate physical work capacity for the demands of daily living and job performance. Due to work demand, most top and middle (executive) managerial employees become physically inactive and experience psychological and other health problems which may lead to hypokinetic diseases and even premature death. The purpose of this study was twofold: to determine leisure-time physical activity and psychological well-being status of executive employees; and to determine the relationship between leisure-time physical activity and psychological well-being status of executive employees in selected African countries. A cross-sectional study design was carried out on a group of 156 (mean age 41.22±10.17) available executive employees from selected African countries. Participants were grouped according to age (≤35 years; 36–46 years and ≥ 46 years). Standardised questionnaires were used to collect the data. Subsequently, total scores were calculated for all variables. Out of 156 participants in the study, 42.9% occupied top level management and 57.1% middle level management positions. When data was analysed according to age groups, 31.4% and 68.6% in the less than 35 years age group were in the top and the middle level management positions respectively. In the age group 36 to 46 years, 47.2% occupied the top level management position and 52.8% occupied the middle level management position. With regard to LTPA, top level managers (71.6%) scored low LTPA compared to the middle level managers (62.9%). In addition, both the top and middle level managers reported bad emotional index (49.3%; 56.2%) and happiness index (41.8%; 37.1%) respectively. Though not significant, LTPA was positively associated with psychological well-being parameters amongst top level managers. The study concluded that both top and middle level managers exhibited low LTPA, and with no participation in high physical activity among top level managers. In addition, more middle level managers reported bad emotional stage than the top level managers, while the top level managers were less happy than the middle level managers. The study therefore recommends urgent strategic intervention programmes for leisure-time physical activity and psychological well-being. / MSc (Biokinetics), North-West University, Potchefstroom Campus, 2014
30

Cloning and expression of human recombinant isoform a of glycine-N-acyltransferase

Grundling, Daniel Andries January 2012 (has links)
Awareness of detoxification, nowadays known as biotransformation, has become an integral part of our daily lives. It is a modern buzz word that is used to promote anything from health food to enhancement of performance in sports. Another lesser known application for detoxification is as a therapy for alleviating symptoms of inborn errors of metabolism. Detoxification is the process where endogenous and xenobiotic metabolites are transformed to less harmful products, in the liver and kidneys, in two phases. Phase 1 detoxification includes oxidation, hydroxylation, dehydrogenation metabolic reduction and hydrolysis. Phase 2 detoxification uses conjugation reactions to increase hydrophillicty of metabolites for excretion in bile and urine. Glycine N-acyltransferse (GLYAT; EC 2.3.1.13) is one of the amino acid conjugation enzymes. There are two variants of human GLYAT. I focused on the full-length mRNA human GLYAT isoform a, with a long term view of using it as a viable therapeutic enzyme for enhanced detoxification of harmful metabolites. I investigated if it is possible to clone and express a biologically active GLYAT. To achieve this goal I used three expression systems: traditional bacterial expression using the pET system; second generation cold shock bacterial expression using the pCOLDTF expression vector to improve solubility of the recombinant protein; and baculovirus expression in insect cells since therein some form of post translation glycosylation of the recombinant protein can occur which might improve solubility and ensure biological activity. The recombinant GLYAT expressed well in all three expression systems but was aggregated and no enzyme activity could be detected. A denature and renature system was also used to collect aggregated recombinant GLYAT and used to try to refold the recombinant protein in appropriate refolding buffers to improve solubility and obtain biological activity. The solubility of the recombinant GLYAT was improved but it remained biologically inactive. / Thesis (MSc (Biochemistry))--North-West University, Potchefstroom Campus, 2013.

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