Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UNIPROT:P00790 (PGA)
 2,475 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Eight human IgA1 myeloma proteins were analysed by SDS-PAGE. These experiments showed that purified IgA1 proteins comprise both fully S-S bonded and partly S-S bonded molecules. Pepsin digestion of the IgA1 proteins yielded three four-chain and two two-chain fragments. The four-chain fragments are likely to be derived from intact IgA through cleavage of its alpha chains at different sites: between the CH2 and CH3 domains or in the hinge region. The occurrence of F(abc) (ab') fragments, with alpha chains of different lengths, showed that the alpha chains of IgA can be cleaved independently at the hinge region site. The two-chain pepsin fragments must originate from IgA molecules, which lack inter-assay-chain disulphide linkages. The fragments F(abc)2 and Fabc tended to form dimers, probably through non-covalent interactions of their CH2 domains. An immunoblotting method was used to identify Fd-, CH2- and CH3-specific anti-IgA antibodies. The CH2-specific antibodies could be subdivided into antibodies recognizing an isotype present on both four-chain and two-chain molecules or on two-chain molecules only.
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PMID:Production and characterization of pepsin fragments of human IgA1 to determine domain-specificity of monoclonal anti-IgA antibodies. 309 70

The pepsin extraction of group A type 1 streptococci for the isolation of M protein fragments was studied at different pH values and at different time intervals. The extracts were compared by SDS PAGE and fused rocket immunoelectrophoresis. Type 1 M protein fragments were prepared in preparative scale by pepsin extraction of type 1 streptococci at pH 5.5 for 60 min. The fragments were separated by affinity chromatography on immobilized fibrinogen and finally purified for sequence studies by gel chromatography. Pepsin extraction of group A type 3 streptococci was also studied at different pH values. In contrast to type 1, the SDS PAGE pattern changed drastically in dependence on the pH. Affinity chromatography on immobilized fibrinogen is also effective in the separation of the pH 5.5 type 3 streptococcal pepsin extract.
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PMID:Type 1 and 3 M-proteins of Streptococcus pyogenes: peptic extraction and fibrinogen binding properties. 313 67

Pepsin-solubilized bovine corium collagen was reconstituted by rapid neutralization in dilute phosphate buffer at temperatures ranging from 10 degrees C-25 degrees C. The resultant fibrils were harvested by centrifugation and resuspended in physiological buffer to a constant protein concentration. The optical density of such suspensions, measured at 410 nm in a 1 mm path length cuvette, exhibited a strong inverse correlation with temperature of fibrillogenesis. The absorbance values of fibrillar suspensions prepared from intact collagen were greater than those observed with suspensions prepared from pepsin-solubilized collagen under similar conditions and demonstrated a reduced dependence on temperature of fibril assembly. The nature of the variation in opacity of fibrillar suspensions prepared from pepsin-solubilized material was further investigated using transmission electron microscopy, trypsin sensitivity, SDS gel electrophoresis and polarimetry. Reconstitution conditions that favored more rapid precipitation (e.g., higher incubation temperatures) tended to produce fibril suspensions of lower opacity (translucent). These translucent suspensions exhibited fibrils that were small in diameter when compared to fibril suspensions of higher opacity. Translucent preparations also contained higher levels of a trypsin sensitive, early melting component and displayed a higher proportion of peptides migrating faster than alpha 2(I) on SDS polyacrylamide gels. Collagen preparations depleted of the early melting component continued to demonstrate the correlation between increased temperature and decreased fibrillar opacity, suggesting that the two phenomena were independent. It is proposed that the unstable components are nicked or shortened collagen helices, presumably generated by pepsinization or the action of endogenous proteases of the bovine corium, which are differentially incorporated into fibrils depending on the conditions of fibril assembly.
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PMID:Collagen fibrillogenesis in vitro: a characterization of fibril quality as a function of assembly conditions. 392 70

Quantification and biosynthesis of type I and type III collagens were determined in skin of control and Fraser mice (CatFraser mutation), which exhibit a genetically determined cataract. Skin organ cultures were labelled with [3H]proline. Pepsin-solubilized collagens were studied using three different approaches: (a) differential salt precipitation at neutral pH, followed by SDS-polyacrylamide gel electrophoresis; (b) differential salt precipitation at acid pH followed by SDS-polyacrylamide gel electrophoresis. (c) CNBr peptide analysis. These methods gave consistent and reproducible results, indicating a selective decrease of type I collagen in Fraser mouse skin as compared to control mouse skin. Metabolic labelling of skin organ cultures showed a decreased specific radioactivity of hydroxy[3H]proline in type I collagen of Fraser mouse skin. The concordant results of these experiments suggest a genetically determined alteration of interstitial collagen metabolism in the Fraser mutation apparently specifically concerning the expression of type I collagen gene(s).
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PMID:Selective decrease of type I collagen synthesis in Fraser mice skin. 393 69

A procollagen in the soluble fraction of rabbit vitreous was isolated by dialysis against dilute acetic acid and partially purified by Bio-Gel A 5M gel filtration. The molecule was identified to be type II procollagen by comparing its segment-long-spacing (SLS) banding pattern with that of standard type II collagen isolated from rabbit articular cartilage. Electron microscopy of the SLS of this type II procollagen revealed a fuzzy propeptide extension at the N-terminal end of the molecule. Pepsin digestion of the procollagen removed this extension, thus converting the molecule into a collagen which had mobility similar to that of pepsin-soluble cartilage type II collagen in SDS-polyacrylamide gel electrophoresis. No inter-chain disulfide bond was found in the propeptide extension when the procollagen samples were electrophoresized with or without mercaptoethanol. Comparison of the cyanogen bromide peptide map of the type II procollagen with that of the pepsin-soluble type II collagen indicated that two extra peptides were present in the digest of procollagen. All of this evidence suggested that the procollagen in the soluble vitreous body of the rabbit eye was a novel type II procollagen with a propeptide extension only at the N-terminus.
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PMID:Identification of type II procollagen in rabbit vitreous. 401 Nov 29

Macromolecular collagen components in normal liver and at the different stages of human liver cirrhosis were studied under various extraction conditions. The collagen content at the typical stage of liver cirrhosis was more than five-fold higher than that of the normal state. Pepsin-solubilized collagens extracted successively accounted for 90% of the total collagen and were subjected to determination of the collagen types by salt differentiated fractionation and SDS-polyacrylamide gel electrophoresis. Both type I and III collagens, especially the former, increased, reflecting enhanced total collagen with the progression of liver cirrhosis. The ratio of type I to type III was 1.02 - 1.22 in normal liver and at the early stage of liver cirrhosis, but increased to 1.58 and 1.60 at the typical and advanced stages of liver cirrhosis, respectively. At the early stage, the remarkable increase in type V collagen started much earlier than at the typical stage when the ratio of type I to type III changed. The enhancement of type V collagen may result from a cell proliferative phenomenon at the earlier stage of liver cirrhosis.
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PMID:Changes of collagen types at various stages of human liver cirrhosis. 643 88

Pepsin-soluble collagen was extracted from three histologically proven cases of chordoma and nucleus pulposus. The collagen types of these materials were investigated by differential salting-out, SDS-PAGE (sodium dodecyl sulphate-polyacrylamide gel electrophoresis) of native collagen and their CNBr (cyanogen bromide) cleaved peptides, and their amino acid compositions. Although the collagen of nucleus pulposus was type II, that of chordoma was largely type I. Collagen of notochord, the origin of nucleus pulposus, is known to be type II. Further investigation is necessary in view of the fact that collagen of chordoma, a tumor believed to be derived from notochord, is not type II.
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PMID:Type of collagen in chordoma. 643 58

We studied biochemically the changes associated with aging and disease in the collagen of articular cartilages and menisci. Pepsin soluble and insoluble collagen were obtained by the method of Miller (1971) from the articular cartilages of seven healthy young and adult, six healthy aged subjects, and of six osteoarthritic and six rheumatoid arthritic patients. One portion of pathological cartilage was histologically examined to eliminate any possible contamination of the fibrous tissue and subchondral bone, and to classify the pathological findings. By the method of Miller, the pepsin soluble and insoluble collagen were also obtained from four adult and six aged menisci. Amino acid composition and carbohydrate contents were studied in insoluble collagen. The type of soluble collagen were analyzed with SDS disc electrophoresis. The amount of crosslinks in insoluble collagen was analyzed by the method of Masuda (1976) using automatic amino acid analyzer. The results obtained where shown as follow: 1) Solubility of collagen by pepsin decreased with aging on articular cartilages and menisci. In osteoarthritis and rheumatoid arthritis, the solubility of collagen by pepsin was different between the samples, and generally higher than that of collagen from the aged articular cartilages. 2) In respect to aldimine crosslinks of insoluble collagen, the dihydroxylysinonorleucine (DHLNL), hydroxylysinonorleucine (HLNL) and lysinonorleucine (LNL) increased with aging. DHLNL and HLNL were present in the nonreduced collagen in vitro. It was shown that the aldimine crosslinks had been already reduced in vivo. 3) The contents of carbohydrate of insoluble collagen from articular cartilage showed lower values than that of type II collagen as described previously. The hexosamine contents increased and those of uronic acid and hexose decreased with aging. In osteoarthritic and rheumatoid arthritic articular cartilages, the contents of uronic acid were lower than that of healthy aged group. The carbohydrate contents of menisci were similar to that of type I collagen. 4) concerning the type of collagen, healthy articular cartilages consisted of type II collagen. In collagen of aged cartilages and those of fibrillated and osteophytic cartilages in osteoarthritic and rheumatoid arthritic patients, the type II collagen were mixed with type I collagen ranging from 13.8% to 64.5%, although the analysis of articular cartilages in this study showed histological characteristics of hyaline cartilage. The type of soluble collagen in adult and aged menisci were composed of type I collagen in spite of aging.
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PMID:[Biochemical study of human articular cartilage and meniscus on aging and joint disease (author's transl)]. 689 84

The inhibitory specificity and stability of ovomucoid from Japanese quail egg white (OMJPQ) were examined to understand its nutritional significance. OMJPQ showed strong inhibitory activities toward trypsins from various origins including human, and the trypsin inhibitions occurred at molar ratios of enzyme to inhibitor between 1/1 and 2/1. On the other hand, an equimolar mixture of the second and third domains of OMJPQ inhibited bovine trypsin more strongly than the corresponding native OMJPQ did. This distinction was partly explained by the presence of steric hindrance on the formation of a 2:1 trypsin-OMJPQ complex. OMJPQ retained about 100% of its original activity over a pH range from 1 to 12 after a 24-h incubation at 37 degrees C. The inhibitor was most thermostable between pH 2 and 5, where more than 70% of its original activity was maintained after a 1-h incubation at 100 degrees C and about 25% of the activity even after a 30-min incubation at 121 degrees C. OMJPQ was also considerably resistant to pepsin attack. Pepsin digestion of the protein resulted in only about 40% loss of the original trypsin-inhibitory activity even after a 24-h digestion. Furthermore, the addition of bovine serum albumin to the digestion mixture brought about rapid elevation in the trypsin-inhibitory activity during an initial 30-min digestion. SDS-PAGE and immunoblot suggested that this was due to the liberation of active inhibitory domains from the native molecule by inter-domain proteolysis.
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PMID:Inhibitory specificity against various trypsins and stability of ovomucoid from Japanese quail egg white. 775 77

Methods were described for the production of Fab and Fab' fragments from chicken egg yolk IgY also referred to as IgG by papain and pepsin digestion respectively. Pepsin digestion was found to be suitable for the large scale preparation and purification of Fab'. Optimum yield of Fab' was obtained after peptic digestion of IgY at pH 4.2 for 9 h at low NaCl concentration. This condition led to the complete digestion of pFc' fragment leaving only the Fab' fragment. By combination of ultrafiltration and anion exchange, and conditions which allowed binding of the small amount of contaminants in the digest to the anion exchange column, pure Fab' fragments were easily obtained in the eluent. The advantage of this approach is that a small column could be used to purify large amount of protein, therefore, improving the efficiency of purification. The Fab and Fab' fragments appeared to be similar on the basis of their molecular weights as determined by SDS-PAGE, reaction of identity in immunodiffusion assay and similar antigen binding activities as shown by ELISA.
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PMID:Production and purification of Fab' fragments from chicken egg yolk immunoglobulin Y (IgY). 831 86


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