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)

A major extracellular matrix glycoprotein, GP140 , synthesized by WI-38 human lung fibroblasts has previously been shown to be collagen-like. A form of GP140 that is related to extracellular matrix GP140 both antigenically and in apparent molecular mass was isolated from human placenta. Types I-VI collagen were isolated from human tissues by limited pepsin digestion, selective salt precipitation, and chromatography. Immunoblot analysis of the collagens and GP140 utilizing affinity-purified polyclonal antiserum directed against extracellular matrix GP140 demonstrated cross-reactivity of antibodies with type VI collagen. Both type VI collagen and matrix GP140 could be digested with bacterial collagenase following reduction with dithiothreitol but were collagenase insensitive under nonreducing conditions, unlike types I-V collagen. Placental and matrix GP140 and type VI collagen were shown to have receptors for 125I-labeled Lens culinaris lectin. Pepsin digestion of WI-38 extracellular matrix GP140 yielded a 64,000-dalton band which co-migrated with subunits of reduced type VI collagen on Coomassie-stained sodium dodecyl sulfate-polyacrylamide gel electrophoresis gels, reacted with anti- GP140 antiserum and 125I-labeled L. culinaris lectin, and was collagenase-sensitive only under reducing conditions. CNBr fragmentation of extracellular matrix GP140 , the 64,000-dalton pepsin-resistant peptide of GP140 and type VI collagen followed by immunoblot analysis using anti- GP140 revealed similarities in peptide maps of GP140 and type VI collagen. Our data strongly suggest that GP140 and type VI collagen share characteristics that differ from those of other collagen types and that intermolecular disulfide bonding appears to stabilize these molecules in their native unreduced form, thus conferring collagenase resistance. Finally, the SC1 and SC2 subunits of type VI collagen appear to be generated by pepsin digestion of GP140 .
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PMID:Pepsin-generated type VI collagen is a degradation product of GP140. 642 26

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

Fibril formation of neutral salt soluble and pepsin-treated type I collagen from rabbit corneal stroma or sclera was compared using a turbidimetric analysis which permits the determination of apparent rate constants and activation energies for the lag and growth phase of collagen fibrillogenesis. Information regarding the lateral growth of fibrils was obtained from the final turbidity values. Neutral salt soluble corneal collagen had smaller rate constants for both the lag and growth phases of fibrillogenesis than scleral collagen. Pepsin treatment decreased the rate constants for both collagens proportionately. The activation energies were higher for type I collagen from cornea than sclera. Pepsin treatment increased the activation energy for both phases of corneal fibril formation but only the growth phase of scleral collagen fibrillogenesis was affected. The extent of lateral fibril growth was compared using the intrinsic turbidity values which are related to the mass per unit fibril length. Neutral salt soluble scleral type I collagen had a significantly higher intrinsic turbidity than did neutral salt soluble corneal collagen indicating that scleral collagen formed thicker fibrils; however, this difference was not retained after pepsin treatment, demonstrating that a helical-telopeptide interaction occurs in corneal type I collagen which influences fibril diameter. The observed differences in the rate constants, activation energies and intrinsic turbidity values indicates that there are molecular differences which are responsible for fibrillar differences of corneal and scleral type I collagens.
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PMID:Kinetic analysis of collagen fibrillogenesis: II. Corneal and scleral type I collagen. 647 70

The rates of proteolytic breakdown for native human hemoglobin (Hb) in CNmet-and oxy-forms, for isolated native alpha- and beta-chains of human Hb with deprotected SH-groups and for apo-Hb--globin at constant temperature 20 degrees as well as for metHb and globin in the temperature range 4-25 degrees were studied. The proteolysis of oxy-forms of proteins was performed in the presence of CN- to prevent the appearance in solution of quickly splitted aqua and hydroxy met-forms. Pepsin (at pH 5.5), trypsin (at pH 7.0 and 8.5) and protease VI (pronase) (at pH 7.0 and 8.5) were used as proteases. The rate of proteolysis was registered simultaneously by proteolysate precipitation in concentrated salt solutions (to determine the content of the native form), by precipitation in aqueous solution of trichloroacetic or perchloric acid and by colouring the terminal NH2-groups by ninhidrin in the total proteolysate. For most cases the data of all the three independent methods fell on a single kinetic curve, each pair protein--protease being represented by their individual curves. Therefore the breakdown of all the protein studied possesses a burst-like ("one-by-one", "all-or-none") character. The protein resistance to the attack by proteolytic enzymes increases in the following order: globin less than oxy-alpha-chain less than metHb less than oxy-beta-chain less than HbO2 congruent to CNmetHb. The use of control repeated proteolysis has made it possible to prove that differences in the rate of proteolytic degradation are not the consequence of spontaneous denaturation of the least unstable forms of proteins in the course of proteolytic reaction but are predetermined by the conformational state of the native macromolecule.
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PMID:[Proteolytic degradation of native hemoglobin and its constituent parts--isolated subunits and globin. I. Kinetic data and the character of the process of the breakdown of native forms]. 681 53

The pyrene-labeling of acid-soluble (type I) and acid-insoluble collagens from young and old rat tail tendon has been investigated. The pyrene excimer fluorescence is associated with stabilized pyrene labels bound to two adjacent aldehydes in monomeric young collagens. Polymeric young collagens, as well as monomeric and polymeric old collagens, tend to lose this specific arrangement. This is shown by salt and new chromatographic fractionation of monomeric and polymeric collagens. During denaturation, pyrene labels are released from saturated aldehydes in both alpha 1 and alpha 2 chains. This unstable pyrene-labeling is stabilized by NaBH4 reduction of the hydrazone bonds between aldehyde groups and pyrene-containing hydrazines. This stabilization reveals that alpha 1 contains more aldehyde groups than does alpha 2 in young collagen. Pepsin-solubilized, acid-insoluble collagens are partly cross-linked and, like acid-soluble collagens, exhibit the fluorescence of pyrene aggregates probably located at unidentified cross-links, different from unsaturated aldehyde-containing cross-links in acid-soluble collagens.
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PMID:Cross-linking and fluorescence of pyrene-labeled collagen. 682 79

Chronic pyelonephritis was induced in young adult cats by the intravenous injection of a human or a feline strain of Escherichia coli after ligation of one ureter for 24 or 48 h. In the 3 cats infected with the feline strain, scarred kidneys from the obstructed side were removed at necropsy 3, 4 and 5 months later. Collagen was extracted from pyelonephritic and normal kidney tissue with dilute acetic acid and limited proteolysis with pepsin. Scarred kidneys gave higher yields of both acid-soluble collagen (normal = 0.57 +/- 0.12 mg per g tissue; scarred = 0.88 +/- 0.10 mg per g tissue) and pepsin-solubilized collagen (normal = 9.69 +/- 1.79 mg per g tissue; scarred = 20.02 +/- 2.84 mg per g tissue). There was no significant increase in the collagen yield from the kidneys of the 2 cats in which mild focal lesions were found 14 and 16 months after infection with the human strain of E. coli. Pepsin released collagens were separated by fractional salt precipitation and identified by agarose gel chromatography and polyacrylamide gel electrophoresis. Normal kidney was shown to contain collagen of Types I, IV and V (AB). The Type IV collagen extracted consisted of a mixture of 4 major pepsin-resistant chains of apparent molecular weights of 150 000, 115 000, 85 000 and 60 000. The collagen extracted from scarred kidneys was predominantly Type I, only trace amounts of Type IV and V components being present. These findings suggest that basement membrane collagens of the kidney are selectively degraded during the atrophy and scarring of chronic feline pyelonephritis and are preferentially replaced by interstitial Type I collagen.
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PMID:Experimental pyelonephritis in the cat: 3. Collagen alterations in renal fibrosis. 684 96

Urinary immunoreactive PGA and PGE, plasma and urinary aldosterone, and plasma renin activity (PRA) were determined in eleven control subjects and four patients with diabetic hyporeninaemic hypoaldosteronism (HH) before and during 4 days of sodium chloride restriction and frusemide administration. Aldosterone and PRA increased steadily in control subjects, but not in patients with HH. Increases in urinary PGA and PGE were observed during volume depletion. The basal levels and increases observed were comparable in both groups. The apparently normal stimulation of PGA and PGE in subjects with diabetic HH suggests that this syndrome is not associated with abnormal prostaglandin metabolism, despite the fact that drug-induced abnormalities of the latter may precipitate or aggravate the clinical syndrome in susceptible individuals. The increase in PGA and PGE following frusemide treatment and salt depletion supports the possibility of a relationship between renal prostaglandin metabolism, frusemide-induced natriuresis and/or renin secretion. While the nature of this relationship remains obscure, the increases in PGA and PGE in the absence of increases in renin-angiotensin levels in subjects with HH suggests that these changes are not due to activation of the renin-angiotensin system.
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PMID:Urinary prostaglandins following frusemide treatment and salt depletion in normal subjects and subjects with diabetic hyporeninaemic hypoaldosteronism. 701 40

The collagen isotypes present at early (6 week) and late (5 month) stages of growing deer antler were isolated and identified. Pepsin-digested collagens were separated by differential salt fractionation, SDS-PAGE and Western blotting and subsequently identified by immunostaining. Cyanogen bromide digestion of antler tissue was used to establish a collagen type-specific pattern of peptides, and these were also identified by immunoblotting. Collagen type I was found to be the major collagen in both early- and late-stage antler. Collagen type II was present in the young antler in small amounts but was not confined to the soft "cartilaginous" tip of the antler. Collagen type XI was found in the pepsin digest of the young antler, but collagen type IX was not present at either stage of antler growth. Collagen type X was found in the young antler in all fractions studied. Microscopic study showed that the deer antler did not possess a discrete growth plate as found in endochondral bone growth. Unequivocal immunolocalization of the different collagen types in the antler were unsuccessful. These results show that, despite the presence in the antler of many cartilage collagens, growth does not occur through a simple endochondral process.
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PMID:Deer antler does not represent a typical endochondral growth system: immunoidentification of collagen type X but little collagen type II in growing antler tissue. 944 Feb 22

Bacillus licheniformis ATCC 9945a is one of the bacterial strains that produce gamma-poly(glutamic acid) (gamma-PGA). The use of carbohydrate medium components for gamma-PGA production was explored. Cells were grown in shake flasks or in controlled pH fermentors using medium formulations that contain different carbon sources. During the cultivations, aliquots were removed to monitor cell growth, carbon utilization, polymer production, and polymer molecular weight. Glucose was a better carbon source than glycerol for cell growth. Furthermore, glucose was utilized at a faster rate than glycerol, citrate, or glutamate. However, by using mixtures of glucose and glycerol in medium formulations, the efficiency of gamma-PGA production increased. For example, by increasing the glycerol in medium formulations from 0 to 40 g/L, the gamma-PGA broth concentration after 96 h increased from 5.7 to 20.5 g/L. Considering that glycerol utilization was low for the glucose/glycerol mixtures studied, it was unclear as to the mechanism by which glycerol leads to enhanced product formation. Cell growth and concomitant gamma-PGA production (12 g/L) at pH 6.5 was possible using glucose as a carbon source if trace amounts (0.5 g/L each) of citrate and glutamate were present in the medium. We suggested that citrate and glutamate were useful in preventing salt precipitation from the medium. In addition, glutamate may be preferred relative to ammonium chloride as a nitrogen source. The conversion of glucose to gamma-PGA by the strain ATCC 9945a was believed to occur by glycolysis of glucose to acetyl-CoA and tricarboxylic acid (TCA) cycle intermediates that were then metabolized via the TCA cycle to form alpha-ketoglutarate, which is a direct glutamate precursor.
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PMID:Effects of glucose and glycerol on gamma-poly(glutamic acid) formation by Bacillus licheniformis ATCC 9945a. 1009 19

In order to check the applicability of the broken-rodlike (BR) chain model, consisting of several rods alternatively joined by flexible random coils, to the conformational analysis of a polypeptide chain in the helix-to-coil transition regions, two relations predicted by the Zimm and Bragg theory and the method with the BR chain model are compared. It is shown that, despite a clear difference between the models employed in the two methods, they give substantially identical results in both probability P(j) that a helical residue is in a helical sequence j units long and averaged helical fraction dependence of the mean-squared radius of gyration. Thus the use of the method with the BR chain model in the conformational analysis of a polypeptide chain could be rationalized, at least, with the same degree of approximation as is assumed in the Zimm and Bragg theory. Using the scattering function for the BR chain model, averaged helical-sequence lengths are evaluated for partially ionized poly(L-glutamic acid) (PGA) in added-salt aqueous solution and nonionized PGA in N-methylacetamide, both in a helical state. As a result, it is shown that the length in the latter molecule is approximately tenfold longer than that in the former one.
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PMID:Applicability of broken-rodlike chain model to conformational analysis of polypeptide chain. 1079 81


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