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Query: UNIPROT:P06889 (Mol)
 630,302 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Tight junctions adjacent to the tumor stromal interface in invading neoplastic cells of human urinary bladder carcinomas were observed. Basal lamina, collagen and elastic fibers, and cellular debris were found next to the tight junctions. An association between microenvironment (i.e., tumor necrosis) of the invading neoplastic cells and tight junction locations was suggested.
Virchows Arch B Cell Pathol Incl Mol Pathol 1979 Jun 29
PMID:Tight junctions adjacent to tumor stromal interface in human invasive transitional cell carcinomas. 4 9

The distribution of disulfide-groups was investigated in the tunica propria of human seminifersou tubules by means of a thiosulfation/Alcian Blue + 0.8 Mol MgCl2-staining reaction. Controls had shown the absence of significant amounts of sulfhydryl- or sulfate-groups in the lamina propria, which groups would also be demonstrated by the method employed. The lamina propria of human seminiferous tubules is rich in disulfide groups. The staining reaction decreases in the region of the tubulus rectus, is only faint in the connective tissue which underlies the epithelium of the rete testis, and is absent in the lamina propria of efferent ducts. It is suggested that microfibrils and type IV collagen (both rich in cystine) are the materials responsible for the histochemical reaction described. The occurrence of multiple layers of basal lamina material (type IV collagen) and bundles of microfibrils is shown in comparative electron microscopic studies.
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PMID:Histochemical demonstration of disulfide-groups in the lamina propria of human seminiferous tubules. 7 13

The molecule of type I collagen from skin consists of two alpha1(I)-chains and one alpha2-chain. The sequence of the entire alpha1-chain comprising 1052 residues is summarily presented and discussed. Apart from the 279 residues of alpha1(I)-CB8 whose sequence has been established for rat skin collagen, all sequences have been determined for calf skin collagen. In order to facilitate sequence analysis, the alpha1-chain was cleaved into defined fragments by cyanogen bromide or hydroxylamine or limited collagenase digestion. Most of the sequence was established by automated stepwise Edman degradation. The alpha1-chain contains two basically different types of sequences: the triple helical region of 1011 amino acid residues in which every third position is occupied by glycine and the N- and C-terminal regions not displaying this type of regularity. Both of these non-triple helical regions carry oxidizable lysine or hydroxylysine residues as functional sites for the intermolecular crosslink formation. Implications of the amino acid sequence for the stability of the triple helix and the fibril as well as for formation of crosslinks are discussed. Evaluation of the sequence in connection with electron microscopical investigations yielded the parameters of the axial arrangement of the molecules within the fibrils. Axial stagger of the molecules by a distance D = 670 angstrom = 233 amino acid residues results in maximal interaction of polar sequence regions of adjacent molecules and similarly of regions of hydrophobic residues. Ordered aggregation of molecules into fibrils is, therefore, regulated by electrostatic and electrophobic forces. Possible loci of intermolecular crosslinks between the alpha1-chains of adjacent molecules may be deduced from the dimensions of the axial aggregation of molecules.
Mol Cell Biochem 1975 Sep 30
PMID:Information contained in the amino acid sequence of the alpha1(I)-chain of collagen and its consequences upon the formation of the triple helix, of fibrils and crosslinks. 17 54

Serum-free media of minced tissue cultures of VX-2 rabbit carcinoma contained a specific collagenolytic activity capable of releasing soluble radioactive peptides from [14C]-labeled collagen fibrils. It was also capable of reducing the viscosity of acid-soluble collagen solutions by cleaving the tropocollagen (TC) molecules primarily at one site to TCA (75%) and TCB (25%) fragments. Three chromatographic fractions were separated by gel filtration: F1, (MW 85-110,000) present in larger amounts in early cultures of younger tumor tissue; F2, (MW-35-40,000) the major component with maximum production in the day 3 media of younger and advanced tumor tissues; F3, (MW 18-22,000) the minor component. Early cultures of younger tumor tissue contained a latent collagenase and were subject to trypsin activation suggesting the presence of inactive enzyme precursors or an enzyme-inhibitor complex.
Mol Cell Biochem 1977 May 31
PMID:Changes in the collagenolytic activity released by primary VX-2 carcinoma cultures as a function of tumor growth. 19 82

Chemical and enzymatic properties of four collagenases newly isolated from anaerobic Clostridium histolyticum, aerobic Achromobacter iophagus, and from two lower eucaryotes, the fungus Entomophthora coronata and the insect Hypoderma lineatum are reviewed. The problems of their biosynthesis and precursors, namely the effect of induction of collagenase and neutral proteinase in Achromobacter by their macromolecular substrates are discussed. The two bacterial collagenases are Zn-metallo-enzymes; the highly purified Clostridium collagenase contains cyst(e)ine, serine phosphate and tryptophan additionally to amino acids reported previously. Achromobacter collagenase has the highest specific activity of all collagenases; it yields by autolysis enzymatically active degraded forms. The active dimer is composed of two identical subunits of molecular weight 35,000. Similarities between Achromobacter collagenase, thermolysin and Bacillus subtilis neutral proteinase in molecular weight, amino acid composition, and amino acids important for the active sites are discussed. The two collagenases from low eucaryotes are serine proteinases; Hypoderma collagenase is homologous to the trypsin family in the amino terminal sequence. The initial cleavage of native collagen by highly purified bacterial collagenases occurs in the central helical part of the alpha chains and not progressively from the amino terminal end. One of the two initial cleavages produced by Achromobacter collagenase is situated in the region cleaved specifically by vertebrate collagenases, but with different bond specificity. The same is true for the insect collagenase. Entomophthora collagenase is a proteinase of broad specificity which also cleaves collagen in its helical parts. All four collagenases also degrade other proteins according to their bond specificity.
Mol Cell Biochem 1979 Jan 26
PMID:Some newly characterized collagenases from procaryotes and lower eucaryotes. 22 May 20

1. Biosynthesis and deposition of collagen, as well as DNA and total proteins, are increased in aortae of rats after 1, 3 and 6 weeks of hypertension. 2. The maximal increase in the rate of synthesis of collagen is observed within one week of hypertension when the stress to the arterial wall is maximal. 3. Reserpine administration prevents hypertension and inhibits the increase of collagen metabolism. 4. At any time of evolution of the hypertension, a linear positive correlation is found between the collagen content in the aorta and the level of blood pressure. 5. These data suggest that synthesis of matrix components by the arterial smooth-muscle cells is controlled by variation in the blood pressure level and is not a direct consequence of circulating humoral factors liberated by the ischaemic kidney.
Clin Sci Mol Med Suppl 1978 Dec
PMID:The relationship between blood pressure and aortic collagen metabolism in renal hypertensive rats. 28 65

1. Normal synovial membrane contains approximately equal proportions of two genetically distinct forms of collagen, types I and III. The proportion of these two collagens is unchanged in rheumatoid synovium but in addition a small amount of basement membrane collagen is present. Tissue culture of rheumatoid synovium confirms the synthesis of both type I and III collagens. 2. In young normal synovium both type I and type III collagens are stabilized by a reducible keto cross-link, which is replaced in adult tissue by an as yet unknown non-reducible cross-link. During the proliferation of the collagen in adult rheumatoid synovium a high proportion of the keto cross-link is present. This cross-link is not susceptible to cleavage by D-penicillamine, nor does the drug have any effect on the rate of synthesis in vitro. The mode of action of D-penicillamine in rheumatoid arthritis does not appear to involve a direct effect on the synovial membrane collagen.
Clin Sci Mol Med 1978 Jul
PMID:Changes in the collagen of synovial membrane in rheumatoid arthritis and effect of D-penicillamine. 35 1

This article summarizes recent ultrastructure findings from our laboratory and documents some of the information accumulated primarily since 1975 from many laboratories. Special attention is given to documentation by scanning electron microscopy which affords insight into platelet activation (adhesion, aggregation, release/secretion) and especially platelet-vessel wall interactions. Structural physiology of platelets is considered in some detail as a basis for understanding platelet disorders contributing to clinical problems of thrombosis and hemorrhage. The impaired ability of von Willebrand platelets to adhere to injured vessel wall is reported using the human umbilical vein perfusion model. Relationships between platelets and blood coagulation factors focus on the exquisite sensitivity of platelets to minute amounts of thrombin. Unmasking of platelet factor 3 sites is identified on activated platelets, after glutaraldehyde fixation, by their reaction ot latex bearing anti-platelet factor 3 markers. The basis for platelet-collagen interactions is reviewed. Conditions for and possible mechanisms behind platelet interaction with vessel wall are discussed. Ex vivo flowing blood-vessel wall models offer opportunities for improved understanding of the platelets role(s) in vascular diseases.
Mol Cell Biochem 1978 Dec 22
PMID:Platelet responses in health and disease. 37 May 50

Somatic cell hybrids between mouse and human cell lines have been used to identify the specific chromosome that governs the synthesis of type I procollagen. Fourteen hybrid clones and subclones were derived independently from crosses between mouse parents [LM (thymidine kinase-negative) or A9 (hypoxanthine phosphoribosyltransferase-negative)] and human cells (human diploid lung fibroblasts WI-38 or diploid skin fibroblasts GM5, GM17, and GM9). The cultures were labeled with [(3)H]proline in modified Eagle's medium without serum. Radioactive procollagens were purified from the medium by the method of Church et al. [(1974) J. Mol. Biol. 86, 785-799]. DEAE-cellulose chromatography was used to separate collagen and type I and type III procollagen. Human type I procollagen was assayed by double immunodiffusion analysis with type I procollagen antibodies prepared by immunizing rabbits with purified human type I procollagen. These analyses combined with karyology and isozyme analyses of each hybrid line have produced evidence for the assignment of the gene for human type I procollagen to chromosome 17. A human microcell-mouse hybrid cell line containing only human chromosome 17 was positive for human type I procollagen, lending further support to the assignment of the human type I procollagen gene to chromosome 17. Finally, by using a hybrid line containing only the long arm of human chromosome 17 translocated onto a mouse chromosome, the type I procollagen gene can be assigned more specifically to the long arm of chromosome 17.
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PMID:Genetics of the connective tissue proteins: assignment of the gene for human type I procollagen to chromosome 17 by analysis of cell hybrids and microcell hybrids. 41 88

The method of hydrogen exchange is used to determine the mobility of acid-soluble collagen molecules from animals with different physiological temperature in terms of equilibrium constants of the formation of micro-unfolding or fluctuating defects of the structure. It has been shown that mobility of the collagen structure correlates with the physiological temperature of the animal from whose tissue collagen was isolated and is mainly determined by the amino acid content of the collagen. It has been shown also that at physiological temperatures characteristic for a particular species the level of collagen mobility is of the same order despite their different thermostability. The conclusion has been drawn that the level of mobility is the main criterion at the natural selection of the amino acid composition of collagens in different animals.
Mol Biol (Mosk)
PMID:[Mobility of collagen structure and temperature adaptation of animals]. 46 Feb 8


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