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)

Pepsin-soluble collagen was isolated from bovine vitreous humor. This collagen showed only one alpha-chain in disc electrophoresis, migrating in the alpha1-chain position and between the alpha- and beta-components some colored bands were visible. The disc electrophoretic patterns of the cyanogen bromide peptides of pepsin-soluble vitreous body collagen and pepsin-soluble type II collagen revealed no identity.
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PMID:[Comparison of the cyanogen bromide peptides of vitreous body collagen and type II collagen (author's transl)]. 34 37

The DNA content of lymphocytes and of basal cells from normal hairless mouse epidermis was measured by microflow fluorometry (MFF). To obtain a relatively pure suspension of epidermal basal cells a combined mechanical and enzymatic method was used. The admixture of differentiating cells into the basal cell fraction after cell separation was 13%. The results were compared with those obtained with conventional Feulgen microspectrophotometry applied to basal cells and dermal lymphocytes in histologic sections. The results from both cytophotometric methods were in good agreement and clearly demonstrated the improved resolution obtained by using microflow fluorometry. When the lymphocytes were not treated with pepsin before being stained with ethidium bromide for MFF, the modal DNA value was consistently below that of the basal cells from the same specimen. Pepsin treatment of lymphocytes, however, increased their fluorescence intensity to the value of epidermal basal cells. The modal DNA value of Feulgen-stained dermal lymphocytes in histologic sections was consistently below that of epidermal basal cells from the same section. The advantage of pepsin treatment for obtaining higher resolution of DNA measurements of basal and differentiating epidermal cells and of lymphocytes was evaluated. The cell cycle distribution of basal cells from epidermis in different states of proliferative activity was determined. Changes in the proportion of cells in S phase were parallel to changes in the 3H-Tdr labeling index.
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PMID:Separation of mouse epidermal basal and differentiating cells for microflow fluorometric measurements: a methodologic study. 82 57

Five pepsinogens were purified from gastric mucosa of Japanese monkey by DEAE-cellulose column chromatography and Sephadex G-100 gel filtration. Each was shown to be homogeneous by polyacrylamide disc gel electrophoresis. They were designated as pepsinogens I, II, III-1, III-2, and III-3, respectively, based on the elution profile on DEAE-cellulose chromatography. The molecular weights of pepsinogens I and II were 48,000 and 43,000, respectively, and those of the other three were 40,000. Each pepsinogen was converted to pepsin [EC 3.4.23.1] by acidification, and some characteristics, e.g. the pH dependence of activity, sensitivity to various inhibitors, stability to alkali, and hydrolytic activity toward N-acetyl-L-phenylalanyl-3,5-diiodo-L-tyrosine (APDT), were determined. The characteristics of pepsins I and II were the same, and those of pepsins III-1, III-2, and III-3 were similar. Pepsin III-3 showed high stability to alkali (pH 8.0), while the others were less stable. Each pepsin hydrolyzed APDT and was inhibited by acid protease-specific inhibitors, e.g. pepstain, diazoacetyl-DL-norleucine methyl ester (DAN), 1,2-epoxy-3-(p-nitrophenoxy)propane (EPNP), and p-bromophenacyl bromide. The compositions of pepsins I and II were the same, indicating that they are the same protein, and those of pepsins III-1, III-2, and III-3 resembled that of human pepsin. The diversity of pepsinogens and pepsins is discussed in comparison with pepsinogens and pepsins from other animals.
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PMID:Pepsinogens and pepsins from gastric mucosa of Japanese Monkey. Purification and characterization. 82 Jun 94

Both the triple-helical and denatured forms of nonfibrillar bovine dermal type I collagen were tested as substrates for the catalytic subunit of cAMP-dependent protein kinase in an in vitro reaction. Native, triple-helical collagen was not phosphorylated, but collagen that had been thermally denatured into individual alpha chains was a substrate for the protein kinase. Catalytic subunit of cAMP-dependent protein kinase phosphorylated denatured collagen to between 3 to 4 mol of phosphate/mol of (alpha 1(I)2 alpha 2(I). Pepsin-solubilized and intact collagens were phosphorylated similarly, as long as each was in a nonhelical conformation. The first 2 mol of phosphate incorporated into type I collagen by the protein kinase were present in the alpha 2(I) chain. The alpha 1(I) chain was only phosphorylated during long incubations in which the stoichiometry exceeded 2 mol of phosphate/mol of (alpha 1(I)2 alpha 2(I). Phosphoserine was the only phosphoamino acid identified in collagen that had been phosphorylated to any degree by the protein kinase. The 2 mol of phosphate incorporated into the alpha 2(I) chain were localized to the alpha 2(I)CB4 cyanogen bromide fragment. The catalytic subunit of cAMP-dependent protein kinase phosphorylated denatured pepsin-solubilized collagen with a Km of 8 microM and a Vmax of approximately 0.1 mumol/min/mg of enzyme. Denatured, but not triple-helical, type I collagen was also phosphorylated by cGMP-dependent protein kinase, although it was a poorer substrate for this enzyme than for the cAMP-dependent protein kinase. Collagen was not a substrate for phospholipid-sensitive Ca2+-dependent protein kinase. These results suggest the potential for nascent alpha chains of type I collagen to be susceptible to phosphorylation by cAMP-dependent protein kinase in vivo prior to triple-helix formation. Such a phosphorylation of collagen could be relevant to the action of cAMP to increase the intracellular degradation of newly synthesized collagen.
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PMID:In vitro phosphorylation of type I collagen by cyclic AMP-dependent protein kinase. 395 36

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

Native type IV collagen was isolated from human placental tissue by pepsin digestion, fractional salt precipitation, reduction and alkylation, a second pepsin digestion, and chromatography on diethylaminoethyl- and carboxymethyl-cellulose. After denaturation, 10 distinct peptides were isolated from this material by molecular sieve, ion-exchange, and high-performance liquid chromatography. All of the peptides were found to have amino acid compositions characteristic of type IV collagen. Analysis of the eight major peptides by amino-terminal amino acid sequencing and by cyanogen bromide and tryptic peptide mapping has revealed the manner in which they are derived from type IV collagen. Pepsin liberates two large peptides by attacking non-triple-helical regions, one derived from the alpha 1 (IV) chain (F2, Mr 90 000) and one derived from the alpha 2 (IV) chain (F3, Mr 75 000). The alpha 1 (IV)-derived F2 peptide is also represented in the pepsin digest by amino-terminal and carboxy-terminal subfragments [F4c (Mr 41 000) and F4a (Mr 60 000)], as is the alpha 2 (IV)-derived F3 peptide [F5 (Mr 28 000) and F4b (Mr 50 000), respectively]. These findings indicate that the molecular regions from which the larger peptides are derived in themselves contain pepsin-sensitive (non-triple-helical) domains. In addition, several of the peptides examined were found to be present in two slightly different forms, suggesting that closely adjacent pepsin-sensitive sites often exist within the type IV collagen molecules. The methods outlined here provide a reliable means by which identifiable type IV collagen peptides can be isolated.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Isolation and characterization of pepsin-solubilized human basement membrane (type IV) collagen peptides. 641 91

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

Kniest dysplasia, a human chondrodysplasia that severely affects skeletal growth, is caused by mutations in the type II collagen gene, COL2A1. We report here on abnormal type II collagen in the cartilage from a lethal Kniest dysplasia case and identify a novel exon-skipping mutation. Screening of cyanogen bromide (CB) peptides from the cartilage samples by SDS-PAGE indicated an abnormality in peptide alpha1(II)CB11. Further peptide mapping and N-terminal sequence analysis showed a 15-amino-acid deletion encoded by exon 15 in about 25% of the alpha1(II) chains in the cartilage. The mutation responsible for exon skipping was found by sequencing amplified genomic DNA. The baby was heterozygous for a G to A transition at the first position of the splice donor of intron 15. Pepsin-solubilized type II collagen from the cartilage matrix contained both normal alpha1(II) and shortened chains expressed from the mutant allele. Trypsin cleaved the native molecules below 37 degrees C selectively at a site within the exon 15-encoded domain of the normal alpha1(II) chains. This is best explained by the coassembly of normal and truncated alpha1(II) chains into heterotrimers in which the triple helix is normally folded in both directions from the deletion site but the latter presents a region of local disruption. The findings support an emerging pattern of COL2A1 mutations that can cause Kniest dysplasia. Short deletions (single or partial exon) clustered in one region of the alpha1(II) chain are favored, resulting in abnormal heterotrimeric molecules that become a significant component of the cartilage extracellular matrix.
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PMID:Incorporation of structurally defective type II collagen into cartilage matrix in kniest chondrodysplasia. 967 39

The alpha2 chain of canine type I collagen was characterized with both sequence analysis of COL1A2 cDNA and chemical analysis of alpha2(I) chains. The complete sequence of canine COL1A2 cDNA was determined from reverse-transcribed and polymerase chain reaction-amplified total RNA from cultured skin fibroblasts. Pepsin-digested and cyanogen bromide-digested type I collagen peptides were analyzed with chromatography, gel electrophoresis, and mass spectrometry. Identity between the sequences of canine and human COL1A2 cDNA was 90.9%, predicting conservation of the 3 cysteine residues required for C-propeptide registration and of cleavage sites for signal peptidase, procollagen N-proteinase, vertebrate collagenase, and procollagen C-proteinase. Conservation of all 50 lysine residues was also predicted, including preservation of the 1:2 asymmetry in the X:Y distribution of the 31 lysine residues in the alpha2(I) triple helix. The human and canine sequences differed in the location of Y-position proline residues and the presence of two unique canine cyanogen bromide peptides, alpha2 CB3b and alpha2 CB3c,5. Knowledge of the conserved and unique features of canine COL1A2 will be valuable for analysis of the expression, synthesis, and structure of type I collagen as well as studies of canine osteogenesis imperfecta.
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PMID:Sequence of canine COL1A2 cDNA: nucleotide substitutions affecting the cyanogen bromide peptide map of the alpha 2(I) chain. 972 Nov 84

Pepsin-solubilized collagen (PSC) was conjugated with carboxymethyl dextran (CMD) using cyanogen bromide to obtain a PSC-CMD film having improved physical properties, physiological properties, and cell affinity. The conjugation was confirmed by the loss of the alpha- and beta-subunit chains and the polymerized band on SDS-PAGE, and by a decrease in the isoelectric point to 3.2. PSC-CMD had a large polymerized structure with the 6 PSC and 228 CMD molecules. PSC-CMD was readily soluble in water, reconstructed a matrix with a less-ordered structure and a characteristic morphological shape, and lost platelet aggregation-inducing ability. The PSC-CMD film, cross-linked by ultraviolet irradiation, exhibited reduced solubility, moderate water vapor permeability, and increased flexibility. PSC-CMD coatings exhibited good cell attachment and growth for fibroblasts and vein endothrical cells.
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PMID:Polymerized structure and improved physical and biochemical material properties of carboxymethyl dextran-conjugated collagen. 1854 95


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