Human neutrophil elastase (HNE) is a uniquely destructive serine protease with the ability to unleash a wave of proteolytic activity by destroying the inhibitors of other proteases. Although this phenomenon forms an important part of the innate immune response to invading pathogens, it is responsible for the collateral host tissue damage observed in chronic conditions such as chronic obstructive pulmonary disease (COPD), and in more acute disorders such as the lung injuries associated with COVID-19 infection. Previously, a combinatorially selected activity-based probe revealed an unexpected substrate preference for oxidised methionine, which suggests a link to oxida-tive pathogen clearance by neutrophils. Here we use oxidised model substrates and inhibitors to confirm this observation and to show that neutrophil elastase is specifically selective for the di-oxygenated methionine sulfone rather than the mono-oxygenated methionine sulfoxide. We also posit a critical role for ordered solvent in the mechanism of HNE discrimination between the two oxidised forms methionine residue. Preference for the sulfone form of oxidised methionine is especially significant. While both host and pathogens have the ability to reduce methionine sulfoxide back to methionine, a biological pathway to reduce methionine sulfone is not known. Taken to-gether, these data suggest that the oxidative activity of neutrophils may create rapidly cleaved elas-tase “super substrates” that directly damage tissue, while initiating a cycle of neutrophil oxidation that increases elastase tissue damage and further neutrophil recruitment.

No description available.

No / Buddlejol (1), a new sterol, has been isolated from the ethyl acetate soluble fraction of the antispasmodic plant Buddleja asiatica along with stigmasterol (2), lignoceric acid (3), taraxerol (4) and alpha-amyrin (5), respectively. The structure of Buddlejol (1) was established as (24S)-stigmast-5,22-diene-7 beta-ethoxy-3 beta-ol by spectral analysis and comparison with closely related structures. Buddlejol revealed to be a competitive inhibitor of chymotrypsin with the Ki value of 10.60 A mu M as indicated by Lineweaver-Burk and Dixon plots and their re-plots against its chymotrypsin inhibition assay, while the other compounds showed less inhibitory potential. The bioassay-guided isolation was stimulated by the preliminary cytotoxic screening of various fractions of B. asiatica.

Le transport de Na+ par ENaC et de Cl- par CFTR, dans l’épithélium des voies aériennes (VA), contrôle la clairance mucociliaire en modulant le volume du liquide de surface (ASL). L’expression et la fonction de ces canaux peuvent être modifiées au cours des maladies inflammatoires chroniques des VA. Dans un modèle de culture primaire de cellules épithéliales nasales humaines (CENH), nous avons démontré l’existence, au cours de la polypose nasosinusienne, d’une chute de la sécrétion de Cl- par CFTR dont l’expression est diminuée par le TGFß1, cytokine de l’inflammation. Nous avons ensuite étudié l’effet de l’élastase, et de son inhibiteur l’EPIhNE4 sur la fonction d’ENaC dans des CENH de patients atteints ou non de mucoviscidose (CF) où l’hyperactivité d’ENaC provoque une déshydratation de l’ASL. Nous avons démontré l’existence d’une activité sérine protéase endogène dans les CENH (patients CF ou non CF) qui, après inhibition, permet de révéler une augmentation de la fonction d’ENaC induite par l’élastase alors inhibable par l’EPI-hNE4. Enfin, nous avons analysé l’effet du 4 phenylbutyrate (4PBA), traitement proposé chez les patients CF, sur le canal ENaC. Le 4- PBA entraîne une augmentation de la fonction d’ENaC dans les CENH de patients CF ou non en adressant des sous-unités du canal à la membrane apicale via la régulation d’une molécule chaperone Hsc70. Le 4-PBA pourrait donc être utilisé dans des pathologies respiratoires avec défaut d’expression d’ENaC mais son usage pourrait être délétère chez les patients CF. La régulation des transports ioniques au cours des maladies inflammatoires chroniques des VA représente donc une cible thérapeutique intéressante / Na+ and Cl- transport by ENaC and CFTR respectively in airway epithelium (AE) control mucociliary clearance by regulating the airway surface liquid (ASL). Ion channel expression and function could be altered by chronic inflammation in AE. In primary cultures from human nasal epithelial cells (HNEC) we demonstrated, in nasal polyposis, a decrease of CFTR expression and Cl- secretion induced by TGFß1, an inflammatory cytokine. We also evaluated the effects of elastase, and its inhibitor EPI-hNE4, on ENaC function in HNEC from cystic fibrosis (CF where ENaC hyperactivity contributes to ASL dehydration) and non CF patients. We detected an endogenous serine protease activity in HNEC (CF or non CF) which, after inhibition, unmask an increase in ENaC function induced by elastase, this increase being then inhibited by EPI-hNE4. Finally, we investigated the effects of a drug now tested in CF patients treatment, the 4-phenylbutyrate (4PBA). 4-PBA promoted ENaC cell surface expression and activity in CF or non CF HNEC by increasing ENaC subunits translocation to plasma membrane via the regulation of Heat Shock Protein 70. 4-PBA treatment could therefore be of interest in the treatment of airway diseases when ENaC trafficking is disrupted but should be used with caution when treating CF patients where ENaC function is already upregulated. All together these results highlight the role of ion transport regulation during chronic inflammatory airway diseases and could lead to new therapeutic strategies

Uma elastase-2 foi recentemente descrita como a principal enzima formadora de angiotensina (Ang) II no perfusato do leito arterial mesentérico (LAM) isolado de rato. Investigamos a interação dessa elastase-2 do perfusato do LAM isolado de rato (E-2LAMR) com alguns substratos e inibidores de elastases-2 e de quimases formadoras de Ang II. Os precursores de Ang II, [Pro11-D-Ala12]-Ang I e substrato tetradecapeptídeo de renina (TDP), foram convertidos em Ang II pela E-2LAMR com eficiências catalíticas de 8,6 min-1mM-1 e 5,1 min-1mM-1, respectivamente, enquanto os substratos cromogênicos N-succinil-Ala-Ala-Pro-Leu-p-nitroanilida e N-succinil-Ala-Ala-Pro-Phe-p-nitroanilida foram hidrolisados pela enzima com eficiências catalíticas de 10,6 min-1mM-1 e 7,6 min-1mM-1, respectivamente. O inibidor peptídico CH 5450 inibiu as atividades da E-2LAMR sobre os substratos Ang I (IC50=49 mM) e N-succinil-Ala-Ala-Pro-Phe-p-nitroanilida (IC50=4,8 mM), enquanto Acetil-Ala-Ala-Pro-Leu-clorometilcetona (Ac-AAPL-CK), um efetivo inibidor de elastases-2 pancreáticas, bloqueou eficientemente a atividade formadora de Ang II da E-2LAMR (IC50=4,5 mM). Em conjunto, esses dados confirmaram e estenderam as similaridades enzimológicas entre elastases-2 pancreáticas e a E-2LAMR. Além disso, a interação até então desconhecida da E-2LAMR com [Pro11-D-Ala12]-Ang I e CH 5450, ambos considerados como reagentes seletivos para quimases, sugere que as evidências para a formação de Ang II in vivo por quimases podem ter sido superestimadas em investigações prévias sobre vias geradoras de Ang II. Experimentos realizados com o LAM isolado de rato analisando o efeito vasoconstritor de Ang II, Ang I, TDP e [Pro11-D-Ala12]-Ang I mostraram a existência de uma via geradora de Ang II independente da ECA, a qual é sensível à quimostatina e Ac-AAPL-CK. Entre os possíveis candidatos para essa via alternativa à ECA aparece a E-2LAMR, uma enzima que não é inibida por captopril e que é sensível à quimostatina e Ac-AAPL-CK. Embora quimases, que também são sensíveis à quimostatina, também possam ser candidatos a essa via independente da ECA, com base nos fatos de que a quimase I de rato tem uma atividade predominante de degradação da Ang II e que não existem relatos na literatura de que quimases sejam sensíveis ao inibidor Ac-AAPL-CK, esses dados em conjunto sugerem um possível papel para a E-2LAMR, mas não quimases, como uma via alternativa à ECA para a geração de Ang II no LAM isolado de rato. A clonagem e o seqüenciamento do cDNA para a E-2LAMR foram alcançados pela combinação de transcrição reversa e reação da polimerase em cadeia. A seqüência do cDNA mostrou-se idêntica à do cDNA para a elastase-2 pancreática de rato; o cDNA tem 909 nucleotídeos mais uma cauda poli (A) e codifica uma preproenzima de 271 amino ácidos. A análise dos supostos amino ácidos no sítio de ligação da Ang I revelou características que poderiam explicar a atividade do tipo carboxidipeptidase necessária para a eficiente conversão de Ang I em Ang II. Adicionalmente, a seqüência revela características estruturais que poderiam contribuir para a ausência de atividade dessa enzima sobre a Ang II. O RNAm para a E-2LAMR foi expresso em LAM, pâncreas, pulmão, coração, rim, fígado e baço, mas não em aorta de rato. Células endoteliais do LAM em cultura expressaram o RNAm para a E-2LAMR e sintetizaram a enzima. A localização intravascular dessa enzima e sua habilidade em formar Ang II e não clivar esse peptídeo indicam que ela poderia ter uma participação significativa como um agente formador de Ang II no sistema cardiovascular. Esses resultados também podem indicar que a E-2LAMR é expressa em vasos de resistência, mas não em vasos de condutância. / An elastase-2 has been recently described as the major angiotensin (Ang) II-forming enzyme of the rat mesenteric arterial bed (MAB) perfusate. Here, we have investigated the interaction of affinity-purified rat MAB elastase-2 with some substrates and inhibitors of both pancreatic elastases-2 and Ang II-forming chymases. The Ang II precursors [Pro11-D-Ala12]-Ang I and renin substrate tetradecaptide (TDP) were converted into Ang II by the rat MAB elastase-2 with catalytic efficiencies of 8.6 min-1mM-1 and 5.1 min-1mM-1, respectively, and the chromogenic substrates N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide and N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide were hydrolyzed by the enzyme with catalytic efficiencies of 10.6 min-1mM-1 and 7.6 min-1mM-1, respectively. The noncleavable peptide inhibitor CH 5450 inhibited the rat MAB elastase-2 activities toward the substrates Ang I (IC50=49 mM) and N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (IC50=4.8 mM), whereas N-acetyl-Ala-Ala-Pro-Leu-chloromethylketone (Ac-AAPL-CK), an effective active site-directed inhibitor of pancreatic elastases-2, efficiently blocked the Ang II-generating activity of the rat MAB enzyme (IC50=4.5 mM). Altogether, these data confirm and extend the enzymological similarities between pancreatic elastases-2 and their rat MAB counterpart. Moreover, the thus far unrealized interaction of rat MAB elastase-2 with [Pro11-D-Ala12]-Ang I and CH 5450, both regarded as selective for chymases, suggests that evidence for the in vivo formation of Ang II by chymases may have been overestimated in previous investigations of Ang II-forming pathways. Experiments carried out in the isolated rat MAB analyzing the vasoconstrictor effect of Ang II, Ang I, TDP, and [Pro11-D-Ala12]-Ang I showed the existence of an ACE-independent pathway for Ang II generation, which is sensitive to chymostatin and Ac-AAPL-CK. Among the possible candidates for this ACE-independent pathway is rat MAB elastase-2, an enzyme that is not inhibited by captopril, and that is sensitive to chymostatin and Ac-AAPL-CK. Although chymases, which are also chymostatin-sensitive enzymes, might also be other possible candidates for this ACE-independent pathway, based on the fact that rat chymase I has a predominant Ang II-degrading activity, and because there are no reports in the literature that chymases are sensitive to Ac-AAPL-CK, altogether these data suggest a possible role for rat MAB elastase-2, but not chymases, as an alternative pathway to ACE for Ang II generation in the isolated rat MAB. The cloning and sequencing of the cDNA for the rat MAB elastase-2 was accomplished by reverse transcription-polymerase chain reaction. The sequence of this cDNA was found identical to the sequence of the rat pancreatic elastase-2; the cDNA is 909 nucleotides in length plus a poly (A) tail and encodes a preproenzyme of 271 amino acids. Analysis of the putative amino acids in the extended Ang I binding site of the rat MAB elastase-2 reveals features that could explain the dipeptidyl carboxypeptidase-like activity required for efficient Ang I to Ang II conversion. Additionally, the sequence reveals structural features that could contribute to the lack of activity of this enzyme toward Ang II. Rat MAB elastase-2 mRNA was expressed in rat mesenteric arteries, pancreas, lung, heart, kidney, liver, and spleen but not in aorta. Cultured mesenteric endothelial cells expressed the mRNA for rat MAB elastase-2 and synthesized the enzyme itself. The intravascular localization of this enzyme and its ability to generate Ang II and not destroy this peptide indicate that it might play a role in the rat cardiovascular system as an Ang II-forming agent. These results may also indicate that rat MAB elastase-2 is expressed in resistance vessels but not in conduit vessels.

Pseudomonas aeruginosa est un pathogène opportuniste responsable de pneumonies. Il est particulièrement impliqué dans la mortalité des patients sous ventilation mécanique et des patients atteints de la mucoviscidose. Ces infections sont difficiles à traiter en raison de l’existence de nombreuses résistances aux antibiotiques chez cette bactérie et des alternatives thérapeutiques s’avèrent donc nécessaires. Nous avons ainsi émis l’hypothèse qu’une application oropharyngée de lactobacilles pourrait permettre de limiter les infections à P. aeruginosa et leurs effets chez les patients concernés. L’objectif principal de ce travail était d’évaluer les effets d’un mélange de lactobacilles dans un modèle murin de pneumonie à P. aeruginosa. Les effets de lactobacilles isolés dans les cavités orales de volontaires sains sur la formation de biofilm et l’activité élastolytique de P. aeruginosa PAO1 ont été mesurés in vitro. Les effets des lactobacilles sélectionnés ont ensuite été évalués dans un modèle d’infection de cellules épithéliales respiratoires(A549) par P. aeruginosa PAO1 puis dans un modèle murin de pneumonie à P. aeruginosa PAO1. Les effets de 87 lactobacilles sur la formation de biofilm et l’activité élastolytique de P. aeruginosa PAO1 ont été déterminés in vitro,aboutissant à la sélection de 3 et 5 souches ayant respectivement inhibé la formation de biofilm et l’activité élastolytique de P. aeruginosa PAO1. Parmi ces souches, L. fermentum K.C6.3.1E, L. paracasei ES.D.88 et L. zeae Od.76,qui étaient les souches les plus actives contre la formation de biofilm ou l’activité élastolytique et les plus acidifiantes lors de croissances dans une salive artificielle, ont été associées dans un mélange testé dans un modèle cellulaire d’infection à P. aeruginosa PAO1. Ce mélange n’a pas eu d’effet cytotoxique et a démontré un effet cytoprotecteur vis-à-vis de l’infection à P. aeruginosa PAO1. In vivo, l’administration intratrachéale de ces mêmes bactéries de façon prophylactique a permis d’une part de réduire les charges pulmonaires en P. aeruginosa PAO1 et d’autre part de réduire ses effets pro-inflammatoires au niveau pulmonaire (IL-6, TNF-α). Ces résultats prometteurs laissent entrevoir la possibilité de nouvelles applications thérapeutiques pour les probiotiques. / Pseudomonas aeruginosa is an opportunistic pathogen that causes pneumonia and which is involved in themortality of mechanically-ventilated or cystic fibrosis patients.These infections are difficult to treat because of the existence of many antibiotic resistances in P. aeruginosa and therapeutic alternatives are needed. Our hypothesis was that the use of probiotics could be an alternative to antibiotic therapy in order to reduce P. aeruginosa infections and its injurious and pro-inflammatory effects in lungs.The main goal of this work was to evaluate the effects of lactobacilli in a murine model of P. aeruginosa pneumonia.The first step of this work was to screen lactobacilli isolated from oral cavities of healthy volunteers against biofilmformation and elastolytic activity of P. aeruginosa PAO1. The effects of selected lactobacilli were then evaluated in amodel of infection of lung epithelial cells by P. aeruginosa PAO1 and in a murine model of P. aeruginosa PAO1pneumonia. Eighty-seven lactobacilli were tested in vitro, leading to the selection of 3 and 5 strains respectively active against biofilm formation and elastolytic activity. The most active strains (L. fermentum K.C6.3.1E, L. paracasei ES.D.88and L. zeae Od.76) toward biofilm formation and elastolytic activity were chosen to be tested in vitro, in a cell model of P. aeruginosa PAO1 infection. This mix showed cytoprotective effect against P. aeruginosa PAO1. Finally, the prophylactic intratracheal administration of the mix of lactobacilli in mice allowed to reduce the pulmonary loads in P.aeruginosa PAO1. In the same time, the pro-inflammatory effects(IL-6 and TNF- α) of the infection were reduced. These promising results suggest the possibility of new therapeutic applications for probiotics.

Uma elastase-2 foi recentemente descrita como a principal enzima formadora de angiotensina (Ang) II no perfusato do leito arterial mesentérico (LAM) isolado de rato. Investigamos a interação dessa elastase-2 do perfusato do LAM isolado de rato (E-2LAMR) com alguns substratos e inibidores de elastases-2 e de quimases formadoras de Ang II. Os precursores de Ang II, [Pro11-D-Ala12]-Ang I e substrato tetradecapeptídeo de renina (TDP), foram convertidos em Ang II pela E-2LAMR com eficiências catalíticas de 8,6 min-1mM-1 e 5,1 min-1mM-1, respectivamente, enquanto os substratos cromogênicos N-succinil-Ala-Ala-Pro-Leu-p-nitroanilida e N-succinil-Ala-Ala-Pro-Phe-p-nitroanilida foram hidrolisados pela enzima com eficiências catalíticas de 10,6 min-1mM-1 e 7,6 min-1mM-1, respectivamente. O inibidor peptídico CH 5450 inibiu as atividades da E-2LAMR sobre os substratos Ang I (IC50=49 mM) e N-succinil-Ala-Ala-Pro-Phe-p-nitroanilida (IC50=4,8 mM), enquanto Acetil-Ala-Ala-Pro-Leu-clorometilcetona (Ac-AAPL-CK), um efetivo inibidor de elastases-2 pancreáticas, bloqueou eficientemente a atividade formadora de Ang II da E-2LAMR (IC50=4,5 mM). Em conjunto, esses dados confirmaram e estenderam as similaridades enzimológicas entre elastases-2 pancreáticas e a E-2LAMR. Além disso, a interação até então desconhecida da E-2LAMR com [Pro11-D-Ala12]-Ang I e CH 5450, ambos considerados como reagentes seletivos para quimases, sugere que as evidências para a formação de Ang II in vivo por quimases podem ter sido superestimadas em investigações prévias sobre vias geradoras de Ang II. Experimentos realizados com o LAM isolado de rato analisando o efeito vasoconstritor de Ang II, Ang I, TDP e [Pro11-D-Ala12]-Ang I mostraram a existência de uma via geradora de Ang II independente da ECA, a qual é sensível à quimostatina e Ac-AAPL-CK. Entre os possíveis candidatos para essa via alternativa à ECA aparece a E-2LAMR, uma enzima que não é inibida por captopril e que é sensível à quimostatina e Ac-AAPL-CK. Embora quimases, que também são sensíveis à quimostatina, também possam ser candidatos a essa via independente da ECA, com base nos fatos de que a quimase I de rato tem uma atividade predominante de degradação da Ang II e que não existem relatos na literatura de que quimases sejam sensíveis ao inibidor Ac-AAPL-CK, esses dados em conjunto sugerem um possível papel para a E-2LAMR, mas não quimases, como uma via alternativa à ECA para a geração de Ang II no LAM isolado de rato. A clonagem e o seqüenciamento do cDNA para a E-2LAMR foram alcançados pela combinação de transcrição reversa e reação da polimerase em cadeia. A seqüência do cDNA mostrou-se idêntica à do cDNA para a elastase-2 pancreática de rato; o cDNA tem 909 nucleotídeos mais uma cauda poli (A) e codifica uma preproenzima de 271 amino ácidos. A análise dos supostos amino ácidos no sítio de ligação da Ang I revelou características que poderiam explicar a atividade do tipo carboxidipeptidase necessária para a eficiente conversão de Ang I em Ang II. Adicionalmente, a seqüência revela características estruturais que poderiam contribuir para a ausência de atividade dessa enzima sobre a Ang II. O RNAm para a E-2LAMR foi expresso em LAM, pâncreas, pulmão, coração, rim, fígado e baço, mas não em aorta de rato. Células endoteliais do LAM em cultura expressaram o RNAm para a E-2LAMR e sintetizaram a enzima. A localização intravascular dessa enzima e sua habilidade em formar Ang II e não clivar esse peptídeo indicam que ela poderia ter uma participação significativa como um agente formador de Ang II no sistema cardiovascular. Esses resultados também podem indicar que a E-2LAMR é expressa em vasos de resistência, mas não em vasos de condutância. / An elastase-2 has been recently described as the major angiotensin (Ang) II-forming enzyme of the rat mesenteric arterial bed (MAB) perfusate. Here, we have investigated the interaction of affinity-purified rat MAB elastase-2 with some substrates and inhibitors of both pancreatic elastases-2 and Ang II-forming chymases. The Ang II precursors [Pro11-D-Ala12]-Ang I and renin substrate tetradecaptide (TDP) were converted into Ang II by the rat MAB elastase-2 with catalytic efficiencies of 8.6 min-1mM-1 and 5.1 min-1mM-1, respectively, and the chromogenic substrates N-succinyl-Ala-Ala-Pro-Leu-p-nitroanilide and N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide were hydrolyzed by the enzyme with catalytic efficiencies of 10.6 min-1mM-1 and 7.6 min-1mM-1, respectively. The noncleavable peptide inhibitor CH 5450 inhibited the rat MAB elastase-2 activities toward the substrates Ang I (IC50=49 mM) and N-succinyl-Ala-Ala-Pro-Phe-p-nitroanilide (IC50=4.8 mM), whereas N-acetyl-Ala-Ala-Pro-Leu-chloromethylketone (Ac-AAPL-CK), an effective active site-directed inhibitor of pancreatic elastases-2, efficiently blocked the Ang II-generating activity of the rat MAB enzyme (IC50=4.5 mM). Altogether, these data confirm and extend the enzymological similarities between pancreatic elastases-2 and their rat MAB counterpart. Moreover, the thus far unrealized interaction of rat MAB elastase-2 with [Pro11-D-Ala12]-Ang I and CH 5450, both regarded as selective for chymases, suggests that evidence for the in vivo formation of Ang II by chymases may have been overestimated in previous investigations of Ang II-forming pathways. Experiments carried out in the isolated rat MAB analyzing the vasoconstrictor effect of Ang II, Ang I, TDP, and [Pro11-D-Ala12]-Ang I showed the existence of an ACE-independent pathway for Ang II generation, which is sensitive to chymostatin and Ac-AAPL-CK. Among the possible candidates for this ACE-independent pathway is rat MAB elastase-2, an enzyme that is not inhibited by captopril, and that is sensitive to chymostatin and Ac-AAPL-CK. Although chymases, which are also chymostatin-sensitive enzymes, might also be other possible candidates for this ACE-independent pathway, based on the fact that rat chymase I has a predominant Ang II-degrading activity, and because there are no reports in the literature that chymases are sensitive to Ac-AAPL-CK, altogether these data suggest a possible role for rat MAB elastase-2, but not chymases, as an alternative pathway to ACE for Ang II generation in the isolated rat MAB. The cloning and sequencing of the cDNA for the rat MAB elastase-2 was accomplished by reverse transcription-polymerase chain reaction. The sequence of this cDNA was found identical to the sequence of the rat pancreatic elastase-2; the cDNA is 909 nucleotides in length plus a poly (A) tail and encodes a preproenzyme of 271 amino acids. Analysis of the putative amino acids in the extended Ang I binding site of the rat MAB elastase-2 reveals features that could explain the dipeptidyl carboxypeptidase-like activity required for efficient Ang I to Ang II conversion. Additionally, the sequence reveals structural features that could contribute to the lack of activity of this enzyme toward Ang II. Rat MAB elastase-2 mRNA was expressed in rat mesenteric arteries, pancreas, lung, heart, kidney, liver, and spleen but not in aorta. Cultured mesenteric endothelial cells expressed the mRNA for rat MAB elastase-2 and synthesized the enzyme itself. The intravascular localization of this enzyme and its ability to generate Ang II and not destroy this peptide indicate that it might play a role in the rat cardiovascular system as an Ang II-forming agent. These results may also indicate that rat MAB elastase-2 is expressed in resistance vessels but not in conduit vessels.

The yeasts Pichia pastoris and Kluyveromyces lactis were used to express several recombinant human proteins for further biochemical characterization. Two substitution variants of recombinant human enteropeptidase light chain (rhEPL) were engineered to modify the extended substrate specificity of this serine protease. Both were secreted as active enzymes in excess of 1.7 mg/L in P. pastoris fermentation broth. The substitution variant rhEPL R96Q showed significantly reduced specificities for the preferred substrate sequences DDDDK and DDDDR; however, the rhEPL Y174R variant displayed improved specificities for these substrate sequences relative to all other reported variants of this enzyme. The neutrophil serine proteases human cathepsin G (hCatG) and human neutrophil elastase (HNE) were expressed in P. pastoris and HNE was also expressed in K. lactis. The recombinant variants rhCatG and rHNE, with intact C-terminal extensions, were expressed as fusion proteins with the soluble heme-binding domain of cytochrome B5 (CytB5) and an N-terminal hexahistidine (6xHis) tag for purification. The CytB5 domain was linked to the native N-termini of active rhCatG and rHNE by the EPLcleavable substrate sequence DDDDK~I, where ~ is the sessile bond. These fusion proteins were directed for secretion. The yeast P. pastoris expressed up to 3.5 mg/L of EPL-activable rHNE in fermentation broth; however, only 200 μg/L of rhCatG could be produced by this method. Recombinant expression in K. lactis never surpassed 100 μg/L of activable rHNE. The CytB5 fusion domain was present in the heme-bound form, conferring a red color and 410 nm absorbance peak to solutions containing the fusion proteins. This absorbance pattern was most readily visible during the purification of CytB5-rHNE from P. pastoris. Human C-reactive protein (hCRP) and the substitution variant CRP E42Q were expressed in recombinant form and secreted by P. pastoris. Both products were found to bind phosphocholine (PCh) in the same manner as native hCRP. Difficulties encountered during purification revealed that wild type recombinant CRP (rCRP) was produced at 2 different molecular masses. The P. pastoris recombinant expression system yielded better results than K. lactis. Bioreactor-scale fermentation in a 5 L vessel facilitated expression and characterization of these recombinant proteins.

<p>Diss. (sammanfattning) Umeå : Umeå universitet, 1994, härtill 5 uppsatser.</p> / digitalisering@umu

Ziel dieser Studie war es, Auswirkungen von subgingival applizierter Hyaluronsäure (Gengigel®) nach scaling and root planing (SRP) auf mikrobiologische Variablen bei Parodontitispatienten nachzuweisen. Dabei wurden die möglichen Zusammenhänge zwischen Ergebnissen der Bakterienspezies und zuvor ermittelten Ergebnissen klinischer Variablen untersucht. An der Untersuchung nahmen 20 Männer und 29 Frauen teil. Es erfolgte eine Randomisierung in zwei Gruppen, bestehend aus einer Testgruppe mit 23 und einer Kontrollgruppe mit 26 Probanden. Bei den Versuchteilnehmern wurde in zwei Sitzungen in einem 24-stündigen Abstand ein SRP mittels Hand- und Ultraschallinstrumenten durchgeführt. Am Ende des SRP wurde in der Testgruppe Gengigel prof® (mit 0,8% Hyaluronsäure) in die parodontalen Taschen eingebracht. Zusätzlich trugen die Probanden der Testgruppe während der folgenden 14 Tage zweimal täglich morgens und abends Gengigel® (0,2%) auf den Gingivarand auf. In der Kontrollgruppe erfolgte das übliche SRP ohne Verwendung von Gengigel®. Alle Probanden wurden zu Beginn der Untersuchung, nach drei und sechs Monaten aus parodontologischer Sicht untersucht. Des Weiteren wurden Proben der Sulkusflüssigkeit für eine spätere Analyse von zehn parodontopathogenen Keimen sowie der Peroxidase- und Granulozytenaktivität gewonnen. Im Gegensatz zur kontinuierlichen Zunahme in der Kontrollgruppe (p=0,035) konnte beim Verlauf der Gesamtbakterienzahl für die Testgruppe keine Veränderung der Keimzahlen (p=0,737) beobachtet werden. In der Testgruppe wurde nach sechs Monaten für Campylobacter rectus, Treponema denticola und Aggregatibacter actinomycetemcomitans eine Reduktion der Keimbelastung festgestellt (p=0,05; p=0,043; p=0,066). Am Ende der Untersuchung waren in der Testgruppe keine Unterschiede in der bakteriellen Besiedlung unterschiedlich tiefer Taschen mehr nachweisbar (p=1). In der Testgruppe bestand eine stark signifikante Korrelation der Granulozytenaktivität mit der Zeit (r=0,443; p<0,0001) und mit der Gesamtbakterienzahl (r=0,336; p=0,009). Die Ergebnisse der Studie weisen auf einen wachstumshemmenden Effekt der Hyaluronsäure auf parodontopathogene Bakterien hin, welcher womöglich auf einer indirekten Interaktion mit dem Immunsystem basiert.