Thesis (Ph.D.)--Tufts University, 2002. / Adviser: Aurelie Edwards. Submitted to the Dept. of Chemical Engineering. Includes bibliographical references (leaves 210-219). Access restricted to members of the Tufts University community. Also available via the World Wide Web;

Diss. (sammanfattning) Uppsala : Univ., 2004. / Härtill 4 uppsatser.

Diss. (sammanfattning) Umeå : Univ., 2007. / Härtill 4 uppsatser.

Thesis (Ph. D.)--University of Hawaii at Manoa, 2004. / Includes bibliographical references (leaves 137-145).

Thesis (M. Med. Sc.)--University of Hong Kong, 2004. / Also available in print.

Thesis (M.S.)--Georgia State University, 2005. / Title from title screen. Roberta Attanasio, committee chair; P.C. Tai, W.C. Hooper, committee members. Electronic text (57 p. : col. ill.) : digital, PDF file. Description based on contents viewed Aug. 15, 2007. Includes bibliographical references (p. 55-57).

Biochemical and immunological studies indicate that rod outer segments (ROS) of bovine photoreceptor cells contain a Mr 240,000 polypeptide related to the ∝-subunit of red blood cell (RBC) spectrin. With the use of sodium dodecyl sulfate gel electrophoresis in conjunction with the immunoblotting technique, monoclonal antibody 4B2 was found to bind to a Mr 240,000 polypeptide in ROS that is distinct from the prominent Mr 220,000 concanavalin A binding glycoprotein. The Mr 240,000 polypeptide is highly susceptible to degradation by endogenous proteases. It does not appear to be an integral membrane protein but is tightly membrane associated since it can be partially extracted from ROS membranes with urea in the absence of detergent. The 4B2 antibody cross-reacted with RBC ghost membranes and bovine brain microsomal membranes. Radioimmune assays and immunoblotting analysis of purified bovine RBC spectrin further revealed that the 4B2 antibody predominantly labelled the ∝-chain of RBC spectrin having an apparent Mr of 240,000. Monoclonal antibody 3A6 was found to bind to a polypeptide with a slightly lower Mr than the 4B2-specific polypeptide. It is also highly susceptible to degradation by endogenous proteases, but unlike the 4B2 antibody, it predominantly labelled the β-chain of RBC spectrin having an apparent M of 220,000. Polyclonal anti-spectrin antibodies that bound to both the ∝ - and β-chain of RBC spectrin predominantly labelled a Mr 240,000 polypeptide of ROS membranes. Two faintly labelled bands in the Mr range of 210,000-220,000 were also observed. These components may represent variants of the β -chain of spectrin that are weakly cross-reacting or present in smaller quantities than the ∝-chain. Immunocytochemical labelling studies using the 4B2 antibody and immunogold-dextran markers indicated that the ROS spectrin-like protein is preferentially localized in the region where the discs come in close contact to the plasma membrane of ROS. Immunoblotting analysis indicated that rhodopsin and peripherin which constitute over 90% of total disc membrane proteins were selectively solubilized in Triton X-100, whereas a set of polypeptides including the 4B2-specific polypeptide and the Mr 220,000 concanavalin A-binding glycoprotein was only partially soluble. Electron microscopy of a negatively stained Triton-extracted ROS pellet revealed a filamentous network. These studies indicate that ROS contain a protein related to RBC spectrin, which may constitute a major component of a filamentous network lining the inner surface of the ROS plasma membrane as previously seen by electron microscopy. This membrane skeletal system may serve to stabilize the ordered ROS structure and maintain a constant distance between the rim region of the discs and the plasma membrane. / Medicine, Faculty of / Biochemistry and Molecular Biology, Department of / Graduate

No description available.

Lecithin:cholesterol acyltransferase (LCAT) was purified 30,000-fold from hog plasma in a homogeneous state as indicated by polyacrylamide gel electrophoresis. The purified enzyme had an apparent molecular weight of 66,000 and was found to contain about 21.4 percent (w/w) carbohydrate. The properties of hog LCAT including amino acid composition were compared with human LCAT. High density lipoprotein (HDL) was isolated from the hog plasma by an immunoaffinity column chromatography. The isolated HDL showed nearly identical lipid-protein composition although it contained additional protein components when it was compared to HDL isolated by a traditional method involving ultracentrifugation.

A fase aguda é caracterizada pela mudança significativa nos níveis de váriasproteínas plasmáticas. As proteínas amilóide sérica A (SAA) e proteína C reativa (PCR), chamadas de proteínas de fase aguda positivas, têm sua concentração plasmática aumentada em até 1000 vezes durante a inflamação. Espera-se que estas proteínas exerçam um papel importante em algumas etapas do processo inflamatório. Para a PCR existem sólidas evidências de sua participação na ativação do sistema complemento, entretanto para a SAA, a função biológica ainda está para ser esclarecida. No plasma, a SAA encontra-se ligada à lipoproteína de densidade alta (HDL), especialmente a fração HDL3. A SAA associa-se à HDL3 através do deslocamento das apolipoproteínas,- preferencialmente a AI e pouco a AlI. Neste trabalho nos propusemos a avaliar a eficiência da passagem de SAA sérica para os focos inflamatórios. Para este fim doseamos, em 20 exsudatos pleurais e 10 exsudatos ascíticos, e respectivos soros, os seguintes parâmetros: proteínas totais (PT), SAA, PCR, apolipoproteína AI, AlI, 8, colesterol total (CT) e triacilgliceróis (TG). As relações exsudato/soro encontrados para estes parâmetros foram: SAA, 0,11 ± 0,14; PCR 0,31 ± 0,20; AI, 0,48 ± 0,26; AlI, 0,63 ± 0,29; 8, 0,46 ± 0,19; PT, 0,67 ± 0,18; CT, 0,34 ± 0,21; TG, 0,36 ± 0,22. Observamos uma forte correlação entre os níveis séricos de PCR versus SAA e entre AI versus All. Para o exsudato foi mantida a correlação forte somente entre AI versus AlI. Nas correlações entre exsudato e soro observamos correlações moderadas apenas para SAA, AlI e PT. Em função dos nossos resultados, concluímos que a proteína de fase aguda SAA tem acesso ao foco inflamatório e que o conteúdo desta proteína em exsudatos é, pelo menos em sua maioria, originário do soro .. A julgar pelos níveis de apo All encontrados no exsudatos, a permeabilidade das membranas que recobrem as cavidades pleurais e ascíticas é maior para HDL3 do que para HDL2 e LDL, fato es e que garante uma passagem eficiente de SAA para as cavidades. A SAA que tem acesso à cavidade deve sofrer extensa proteólise e/ou associar-se eficientemente às células pois a relação de concentrações exsudato/soro encontrada para SAA é menor que para as demais proteínas analisadas. / Inflammation is characterized by profound changes in the serum leveis of acute phase proteins. The huge increase (up to a 1000 fold) in protein serum amyloid A (SAA) and C reactive protein (CRP) suggests that both proteins exert an important role in the inflammatory processo Although it is known the participation of CRP in the activation of the complement complex, the biological role of SAA is not clear yet. In plasma, SAA is associated to the high density lipoprotein (HDL), especially the HDL3 fraction. The association of SAA to HDL3 causes the displacement of the apolipoproteins A-ll and, especially, A-I. The goal of this study was to evaluate the efficiency of the SAA passage from serum to the inflammatory focus. With this purpose we determined total protein (TP), SAA, PC R, A-I, A-ll, apolipoprotein B (B), total cholesterol (TC) and triglicerides (TG) in 20 samples of pleural exudates and 10 samples of ascitic exudates, and respective serum samples. The ratio exudate/serum found were: SAA, 0, 11±0, 14; CRP 0,31±0,20; A-I, 0,48±O,26; A-ll, 0,63±O,29; 8, 0,46±0, 19; TP, 0,67±0,18; TC, 0,34±0,21; TG, 0,36±0,22. There was a high correlation of the serum leveis of CRP versus SAA and AI versus A-ll. A high correlation in the exudate was only found for AI versus All. The correlation between exudate and serum were moderate and were found only for SAA, A-ll and TP. In conclusion we observed that SAA has access to the exudate and that the content of SAA in the exudate is mainly originated from serum. Considering the leveis of A-ll found in the exudates, we supposed that the permeability of the membranes that cover the pleural and ascitic cavities is higher for HDL3 than for HDL2 and LDL. SAA in the inflamed pleural cavity might suffer an extensive proteolysis and/or efficient association to cells because the ratio exudate/serum found for SAA was lower than for other proteins