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Tvaroška I. Glycosylation Modulates the Structure and Functions of Collagen: A Review. Molecules 2024; 29:1417. [PMID: 38611696 PMCID: PMC11012932 DOI: 10.3390/molecules29071417] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 03/19/2024] [Accepted: 03/20/2024] [Indexed: 04/14/2024] Open
Abstract
Collagens are fundamental constituents of the extracellular matrix and are the most abundant proteins in mammals. Collagens belong to the family of fibrous or fiber-forming proteins that self-assemble into fibrils that define their mechanical properties and biological functions. Up to now, 28 members of the collagen superfamily have been recognized. Collagen biosynthesis occurs in the endoplasmic reticulum, where specific post-translational modification-glycosylation-is also carried out. The glycosylation of collagens is very specific and adds β-d-galactopyranose and β-d-Glcp-(1→2)-d-Galp disaccharide through β-O-linkage to hydroxylysine. Several glycosyltransferases, namely COLGALT1, COLGALT2, LH3, and PGGHG glucosidase, were associated the with glycosylation of collagens, and recently, the crystal structure of LH3 has been solved. Although not fully understood, it is clear that the glycosylation of collagens influences collagen secretion and the alignment of collagen fibrils. A growing body of evidence also associates the glycosylation of collagen with its functions and various human diseases. Recent progress in understanding collagen glycosylation allows for the exploitation of its therapeutic potential and the discovery of new agents. This review will discuss the relevant contributions to understanding the glycosylation of collagens. Then, glycosyltransferases involved in collagen glycosylation, their structure, and catalytic mechanism will be surveyed. Furthermore, the involvement of glycosylation in collagen functions and collagen glycosylation-related diseases will be discussed.
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Affiliation(s)
- Igor Tvaroška
- Institute of Chemistry, Slovak Academy of Sciences, 845 38 Bratislava, Slovakia
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2
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Core glycosylation of collagen is initiated by two beta(1-O)galactosyltransferases. Mol Cell Biol 2008; 29:943-52. [PMID: 19075007 DOI: 10.1128/mcb.02085-07] [Citation(s) in RCA: 106] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Collagen is a trimer of three left-handed alpha chains representing repeats of the motif Gly-X-Y, where (hydroxy)proline and (hydroxy)lysine residues are often found at positions X and Y. Selected hydroxylysines are further modified by the addition of galactose and glucose-galactose units. Collagen glycosylation takes place in the endoplasmic reticulum before triple-helix formation and is mediated by beta(1-O)galactosyl- and alpha(1-2)glucosyltransferase enzymes. We have identified two collagen galactosyltransferases using affinity chromatography and tandem mass spectrometry protein sequencing. The two collagen beta(1-O)galactosyltransferases corresponded to the GLT25D1 and GLT25D2 proteins. Recombinant GLT25D1 and GLT25D2 enzymes showed a strong galactosyltransferase activity toward various types of collagen and toward the serum mannose-binding lectin MBL, which contains a collagen domain. Amino acid analysis of the products of GLT25D1 and GLT25D2 reactions confirmed the transfer of galactose to hydroxylysine residues. The GLT25D1 gene is constitutively expressed in human tissues, whereas the GLT25D2 gene is expressed only at low levels in the nervous system. The GLT25D1 and GLT25D2 enzymes are similar to CEECAM1, to which we could not attribute any collagen galactosyltransferase activity. The GLT25D1 and GLT25D2 genes now allow addressing of the biological significance of collagen glycosylation and the importance of this posttranslational modification in the etiology of connective tissue disorders.
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Myllylä R, Wang C, Heikkinen J, Juffer A, Lampela O, Risteli M, Ruotsalainen H, Salo A, Sipilä L. Expanding the lysyl hydroxylase toolbox: New insights into the localization and activities of lysyl hydroxylase 3 (LH3). J Cell Physiol 2007; 212:323-9. [PMID: 17516569 DOI: 10.1002/jcp.21036] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Hydroxylysine and its glycosylated forms, galactosylhydroxylysine and glucosylgalactosylhydroxylysine, are post-translational modifications unique to collagenous sequences. They are found in collagens and in many proteins having a collagenous domain in their structure. Since the last published reviews, significant new data have accumulated regarding these modifications. One of the lysyl hydroxylase isoforms, lysyl hydroxylase 3 (LH3), has been shown to possess three catalytic activities required sequentially to produce hydroxylysine and its glycosylated forms, that is, the lysyl hydroxylase (LH), galactosyltransferase (GT), and glucosyltransferase (GGT) activities. Studies on mouse models have revealed the importance of these different activities of LH3 in vivo. LH3 is the main molecule responsible for GGT activity in mouse embryos. A lack of this activity causes intracellular accumulation of type IV collagen, which disrupts the formation of basement membranes (BMs) during mouse embryogenesis and leads to embryonic lethality. The specific inactivation of the LH activity of LH3 causes minor alterations in the structure of the BM and collagen fibril organization, but does not affect the lifespan of mutated mice. Recent data from zebrafish demonstrate that growth cone migration depends critically on the LH3 glycosyltransferase domain. LH3 is located in the ER loosely associated with the membranes, but, unlike the other isoforms, LH3 is also found in the extracellular space in some tissues. LH3 is able to adjust the amount of hydroxylysine and hydroxylysine-linked carbohydrates of extracellular proteins in their native conformation, suggesting that it may have a role in matrix remodeling.
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Affiliation(s)
- Raili Myllylä
- Department of Biochemistry, Biocenter Oulu, University of Oulu, Finland.
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Beyer TA, Sadler JE, Rearick JI, Paulson JC, Hill RL. Glycosyltransferases and their use in assessing oligosaccharide structure and structure-function relationships. ADVANCES IN ENZYMOLOGY AND RELATED AREAS OF MOLECULAR BIOLOGY 2006; 52:23-175. [PMID: 6784450 DOI: 10.1002/9780470122976.ch2] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
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Wang C, Luosujärvi H, Heikkinen J, Risteli M, Uitto L, Myllylä R. The third activity for lysyl hydroxylase 3: galactosylation of hydroxylysyl residues in collagens in vitro. Matrix Biol 2002; 21:559-66. [PMID: 12475640 DOI: 10.1016/s0945-053x(02)00071-9] [Citation(s) in RCA: 80] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Lysyl hydroxylase (LH, EC 1.14.11.4), galactosyltransferase (EC 2.4.1.50) and glucosyltransferase (EC 2.4.1.66) are enzymes involved in posttranslational modifications of collagens. They sequentially modify lysyl residues in specific positions to hydroxylysyl, galactosylhydroxylysyl and glucosylgalactosyl hydroxylysyl residues. These structures are unique to collagens and essential for their functional activity. Lysines and hydroxylysines form collagen cross-links. Hydroxylysine derived cross-links, usually as glycosylated forms, occur especially in weight-bearing and mineralized tissues. The detailed functions of the hydroxylysyl and hydroxylysyl linked carbohydrate structures are not known, however. Hydroxylysine linked carbohydrates are found mainly in collagens, but recent reports indicate that these structures are also present and probably have an important function in other proteins. Earlier we have shown that human LH3, but not isoforms LH1, LH2a and LH2b, possesses both LH and glucosyltransferase activity (J. Biol. Chem. 275 (2000) 36158). In this paper we demonstrate that galactosyltransferase activity is also associated with the same gene product, thus indicating that one gene product can catalyze all three consecutive steps in hydroxylysine linked carbohydrate formation. In vitro mutagenesis experiments indicate that Cys(144) and aspartates in positions 187-191 of LH3 are important for the galactosyltransferase activity. Our results suggest that manipulation of the gene for LH3 can be used to selectively alter the glycosylation and hydroxylation reactions, and provides a new tool to clarify the functions of the unique hydroxylysine linked carbohydrates in collagens and other proteins.
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Affiliation(s)
- Chunguang Wang
- Department of Biochemistry, University of Oulu, PO Box 3000, FIN-90014, Oulu, Finland
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6
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Iwase H, Ishii I, Hamazaki H, Hotta K. Detection of uridine 5'-diphosphate glucose-collagen glucosyltransferase activity by high-performance liquid chromatography and possible participation of a novel intermediate as a glucose donor in collagen biosynthesis. JOURNAL OF CHROMATOGRAPHY 1987; 417:403-8. [PMID: 2958491 DOI: 10.1016/0378-4347(87)80136-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- H Iwase
- Department of Biochemistry, School of Medicine, Kitasato University, Kanagawa, Japan
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Ram BP, Munjal DD. Galactosyltransferases: physical, chemical, and biological aspects. CRC CRITICAL REVIEWS IN BIOCHEMISTRY 1985; 17:257-311. [PMID: 3920003 DOI: 10.3109/10409238509113606] [Citation(s) in RCA: 41] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Galactosyltransferases (GTs) are one of the members of a family of enzymes called glycosyltransferases involved in the biosynthesis of complex carbohydrates. These enzymes catalyze the transfer of galactose from UDP-galactose to an acceptor (glycoprotein, glycolipid) containing terminal N-acetylglucosamine or N-acetylgalactosamine residue. GTs occur in soluble (milk, serum, effusions, etc.) and insoluble (membrane) forms. The GT activities on the outer surface of the cells have been correlated with a host of cellular interactions, including fertilization, cell migration, embryonic induction, chondrogenesis, contact inhibition of growth, cell adhesion, hemostasis, intestinal cell differentiation, and immune recognition. GTs have been purified to homogeneity using affinity chromatography. Most GTs are found active in the pH range 6 to 8 and at temperatures between 35 to 40 degrees C. Manganese is an essential co-factor for GT activity. Isoenzymes of GT have been recognized, especially in tumor tissues, malignant effusions, and sera of cancer patients using polyacrylamide gel electrophoresis in the presence and absence of SDS. Depending on the source of the enzyme, the molecular weights of GTs range between 40,000 to 80,000 daltons. Carcinoma-associated GT isoenzyme has been reported to have a higher molecular weight than the normal GT isoenzyme. Development of monoclonal antibody against the cancer-specific GT isoenzyme will provide help in the development of an immunoassay for the measurement of this isoenzyme in the sera and an aid in the radioimmunolocalization of the tumors in cancer patients.
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Vittur F, Stagni N, Moro L, de Bernard B. Alkaline phosphatase binds to collagen; a hypothesis on the mechanism of extravesicular mineralization in epiphyseal cartilage. EXPERIENTIA 1984; 40:836-7. [PMID: 6468592 DOI: 10.1007/bf01951980] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Affinity chromatography on Sepharose 4B-collagen gels was used to test the affinity of alkaline phosphatase for collagen. Results indicate that alkaline phosphatase of preosseous cartilage binds to collagen probably by electrostatic interactions, this interaction is inhibited by proteoglycan subunits. These results suggest that, in vivo, the formation of a collagen-alkaline phosphatase complex may be a step of the process leading to cartilage calcification.
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Purification and characterization of a murine basement membrane collagen-degrading enzyme secreted by metastatic tumor cells. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32829-1] [Citation(s) in RCA: 153] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
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11
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Kivirikko KI, Myllylä R. Posttranslational enzymes in the biosynthesis of collagen: intracellular enzymes. Methods Enzymol 1982; 82 Pt A:245-304. [PMID: 6210830 DOI: 10.1016/0076-6879(82)82067-3] [Citation(s) in RCA: 302] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
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12
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Abstract
This review summarizes the use of biospecific chromatography techniques in the purification of mammalian glycosyltransferases. Ligands that are analogues of donor or acceptor substrates have been linked to cyanogen bromide-activated agarose for use as affinity adsorbents. Immobilized lectins have been employed to recognize the carbohydrate moieties of glycosyltransferase and remove them from complex mixtures. The application of these methods has permitted extensive purification of many membrane-bound glycosyltransferases, some to homogeneity.
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Turpeenniemi-Hujanen TM, Puistola U, Kivirikko KI. Human lysyl hydroxylase: purification to homogeneity, partial characterization and comparison of catalytic properties with those of a mutant enzyme from Ehlers-Danlos syndrome type VI fibroblasts. COLLAGEN AND RELATED RESEARCH 1981; 1:355-66. [PMID: 6809411 DOI: 10.1016/s0174-173x(81)80012-x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Lysyl hydroxylase was isolated as an essentially homogeneous protein from human fetal tissues and as a homogeneous protein from placental tissue by a procedure involving ammonium sulfate fractionation, affinity chromatography on concanavalin A-agarose, affinity chromatography on collagen linked to agarose and gel filtration. The specific activity of the best enzyme preparations from human fetal tissues was about 80,000 times, and from human placenta about 63,000 times that in the 15,000 X g supernatant of the corresponding tissue homogenate. The molecular weight of lysyl hydroxylase from both sources was about 190,000 by gel filtration, and that of the enzyme subunit about 85,000 by sodium dodecyl sulfate-polyacrylamide gel electrophoresis. The specific activity and molecular properties reported are very similar to those of pure chick-embryo lysyl hydroxylase, and the Km values for type I protocollagen substrate, and synthetic peptide substrate and all the co-substrates of the human placenta enzyme are likewise very similar to those of the chick-embryo enzyme. No difference in the Km values for type I protocollagen or any of the co-substrates was found between the human placenta enzyme and a crude lysyl hydroxylase from the skin fibroblasts of a patient with the type VI variant of the Ehlers-Danlos syndrome.
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Turpeenniemi-Hujanen TM, Puistola U, Kivirikko KI. Isolation of lysyl hydroxylase, an enzyme of collagen synthesis, from chick embryos as a homogeneous protein. Biochem J 1980; 189:247-53. [PMID: 6779811 PMCID: PMC1161995 DOI: 10.1042/bj1890247] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Two procedures are reported for the purification of lysyl hydroxylase, both procedures involving (NH4)2SO4 fractionation, affinity chromatography on concanavalin A-agarose and elution of the column with ethylene glycol. The additional steps in procedure A consist of gel filtration and chromatography on a hydroxyapatite column, and in procedure B of affinity chromatography on collagen linked to agarose and gel filtration. The best preparations obtained with either of the two procedures were pure when examined by sodium dodecyl sulphate-polyacrylamide-disc-gel or slab-gel electrophoresis, but about half of the preparations obtained by procedure A had minor contaminants. The specific activity of a typical preparation purified by procedure B was 13 4000 times that of the 15 000 g supernatant of the chick-embryo homogenate, with a recovery of about 4%. The molecular weight of the pure enzyme was bout 200 000 by gel filtration, and that of the enzyme subunit about 85 000 by sodium dodecyl sulphate/polyacrylamide-disc-gel or slab-gel electrophoresis. It is suggested that the active enzyme is a dimer consisting of only one type of monomer, and that a previously described enzyme form with an apparent molecular weight of about 550 000 is a polymeric form of this dimer. The catalytic-centre activity of the pure enzyme, as determined with a saturating concentration of a synthetic peptide substrate and under conditions specified, was about 3-4 mol/s per mol.
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Leunis JC, Smith DF, Nwokoro N, Fishback BL, Wu C, Jamieson GA. The distribution of collagen:glucosyltransferase in human blood cells and plasma. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 611:79-86. [PMID: 7350920 DOI: 10.1016/0005-2744(80)90044-3] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Collagen:glucosyltransferase (UDP-glucose:5-hydroxylysine-collagen glucosyltransferase, EC 2.4.1.66) present in platelets, plasma, granulocytes and lymphocytes has been compared in order to determine whether the platelet enzyme has unique properties or distribution which would support a possible role in platelet-collagen interaction. The enzyme was purified 5400-fold from human plasma and 4400 from human platelets. The two enzymes were similar in terms of Km values for reacting with galactosylhydroxylysine (2.75 mM) and UDPglucose (7.4 microM), optimal Mn2+ concentration (10--15 mM) and pH optimum (7.0). The enzyme was not detectable in red cells. As in platelets, the enzyme was detected in membrane-bound and soluble forms in lymphocytes and granulocytes. Identical mobilities were obtained after elution following polyacrylamide gel electrophoresis of the enzymes from plasma, platelets, granulocytes and lymphocytes. These studies do not support a unique role for the collagen:glucosyltransferase of platelets in platelet-collagen interaction.
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Myllylä R, Anttinen H, Kivirikko KI. Metal activation of galactosylhydroxylysyl glucosyltransferase, an intracellular enzyme of collagen biosynthesis. EUROPEAN JOURNAL OF BIOCHEMISTRY 1979; 101:261-9. [PMID: 510309 DOI: 10.1111/j.1432-1033.1979.tb04239.x] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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17
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Prockop DJ, Kivirikko KI, Tuderman L, Guzman NA. The biosynthesis of collagen and its disorders (first of two parts). N Engl J Med 1979; 301:13-23. [PMID: 449904 DOI: 10.1056/nejm197907053010104] [Citation(s) in RCA: 849] [Impact Index Per Article: 18.9] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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18
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Kivirikko KI, Myllylä R. Collagen glycosyltransferases. INTERNATIONAL REVIEW OF CONNECTIVE TISSUE RESEARCH 1979; 8:23-72. [PMID: 389860 DOI: 10.1016/b978-0-12-363708-6.50008-4] [Citation(s) in RCA: 115] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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Anttinen H, Myllylä R, Kivirikko KI. Further characterization of galactosylhydroxylysyl glucosyltransferase from chick embryos. Amino acid composition and acceptor specificity. Biochem J 1978; 175:737-42. [PMID: 743222 PMCID: PMC1186124 DOI: 10.1042/bj1750737] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
A modified purification procedure, consisting of affinity chromatographies on concanavalin A-agarose, collagen-agarose and UDP-glucose-derivative-agarose and one gel filtration, is reported for galactosylhydroxylysyl glucosyltransferase. The enzyme obtained is entirely pure when studied by sodium dodecyl sulphate/polyacrylamide-gel electrophoresis. The enzyme protein was rich in glutamic acid + glutamine, aspartic acid + asparagine, glycine and alanine. The enzyme catalysed no significant glucose transfer to any of the glycoproteins tested, except for collagens. This included all the glycoproteins that have previously served as glucosyl acceptors for impure enzyme preparations, thus indicating a high degree of specificity of the enzyme for galactosylhydroxylysine. Galactosylsphingosine would act as a glucosyl acceptor, however. This compound has a close structural similarity to galactosylhydroxylysine in that they both have an unsubstituted amino group next to the hydroxy group to which the galactose is attached.
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Abstract
Optimum extraction of collagen galactosyltransferase activity from chick embryos required relatively high concentrations of detergent and salt. The activity was inhibited by concanavalin A, and the enzyme had a high affinity for columns of this lectin coupled to agarose; these results suggest the presence of carbohydrate units in the enzyme molecule. Collagen galactosyltransferase was highly labile, and only 1% of the originally bound enzyme activity could be eluted from the concanavalin A-agarose column with a buffer containing methyl glucoside and ethylene glycol. The purification of the activity over the original supernatant of chick embryo homogenate was 250-300-fold, with the optimum reaction conditions for the purified transferase differing somewhat from those for crude enzyme preparations. The reaction was inhibited by glucose-free basement-membrane collagen, UDP and galactosylhydroxylsine, and also by Co2+ and a number of compounds resembling UDP-galactose. Hydroxylysine was also a weak inhibitor. Immobilized hydroxylysine and UDP-glucuronic acid did not bind the collagen galactosyltransferase, but the enzyme was retarded in a column of UDP-galacturonic acid linked to agarose.
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Anttinen H, Myllylä R, Kivirikko KI. Hydrophobic and carbohydrate-recognition chromatographies of collagen glucosyltransferase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1977; 78:11-7. [PMID: 562261 DOI: 10.1111/j.1432-1033.1977.tb11708.x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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Smith DF, Kosow DP, Wu C, Jamieson GA. Characterization of human platelet UDPglucose-collagen glucosyltransferase using a new rapid assay. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 483:263-78. [PMID: 19064 DOI: 10.1016/0005-2744(77)90055-9] [Citation(s) in RCA: 26] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
A rapid and specific assay has been developed for UDPglucose-collagen glucosyltransferase (UDPglucose: 5-hydroxylysine-collagen glucosyltransferase, EC 2.4.1.66) using galactosylhydroxylysine (Gal-Hyl) as acceptor. Studies with intact human platelets and isolated plasma membranes indicated that about 5--10% of the total activity was surface bound and the rest was of cytoplasmic origin. The two forms of the enzyme had similar broad pH optima (6.5--8.0), Km values for UDPglucose (5 muM) and Gal-Hyl (approx. 4 mM) and for optimal manganese concentrations (25 mM). The soluble form of the enzyme was purified 80-fold. The reaction mechanism was determined as being rapid equilibrium random BiBi + dead end complex or ordered BiBi with UDPglucose being the first substrate to bind. Using Gal-Hyl bound in purified alpha 1 chain of chick skin collagen, a Km value three orders of magnitude less (2 muM) was found than for free Gal-Hyl and the manganese requirement decreased to 2 mM. These results suggest that the binding to the enzyme of Gal-Hyl in the collagen molecule is enhanced by the presence of the protein portion so that the enzyme may be capable of recognizing not only the carbohydrate side chains but also the primary structure of collagen.
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Kirschenbaum DM. Molar absorptivity and A 1% 1cm values for proteins at selected wavelengths of the ultraviolet and visible regions. XIII. Anal Biochem 1977; 81:220-46. [PMID: 332005 DOI: 10.1016/0003-2697(77)90615-7] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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Anttinen H, Oikarinen A, Kivirikko KI. Age-related changes in human skin collagen galactosyltransferase and collagen glucosyltransferase activities. Clin Chim Acta 1977; 76:95-101. [PMID: 856504 DOI: 10.1016/0009-8981(77)90122-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
Collagen galactosyltransferase and collagen glucosyltransferase activities were assayed in human skin specimens of about 100 mg wet weight. The assay of the glucosyltransferase activity was found to be highly specific. The assay of the galactosyltransferase activity was somewhat less specific, but there was no difference in specificity between the foetal and adult human skin samples. The activities of the two collagen glycosyltransferases in human skin extract were found to vary with age, being highest in foetal skin, and higher in the skin of young children that in that of adults. The galactosyltransferase and glucosyltransferase activities in foetal skin were respectively about 4 times and 6 times those in adult skin. The magnitudes of the changes with age in the two collagen glycosyltransferase activities were smaller than those occurring in the activities of the two other intracellular enzymes of collagen biosynthesis namely prolyl and lysyl hydroxylase. This difference suggests that the four intracellular enzyme activities of collagen biosynthesis are not regulated in an identical manner.
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Myllylä R, Anttinen H, Risteli L, Kivirikko KI. Isolation of collagen glucosyltransferase as a homogeneous protein from chick embryos. BIOCHIMICA ET BIOPHYSICA ACTA 1977; 480:113-21. [PMID: 556672 DOI: 10.1016/0005-2744(77)90326-6] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Collagen glucosyltransferase was isolated as a homogeneous protein from chick embryos by a procedure consisting of ammonium sulphate fractionation, two affinity chromatographies and two gel filtrations. The specific activity of the purified enzyme was 32,000 times that of the 15,000 x g supernatant of the embryo homogenate, and the enzyme was pure when examined by sodium dodecyl sulphate polyacrylamide gel electrophoresis using three different gel compositions. The molecular weight of the enzyme was about 72,000-78,000 by sodium dodecyl sulphate polyacrylamide gel electrophoresis, the value being dependent on the gel composition. The apparent molecular weight by gel filtration was dependent on the purity and protein concentration. The sedimentation coefficient S20,w was 4.7. The data suggest that the enzyme molecule consists of one polypeptide chain.
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Myllylä R. Studies on the mechanism of collagen glucosyltransferase reaction. EUROPEAN JOURNAL OF BIOCHEMISTRY 1976; 70:225-31. [PMID: 1009926 DOI: 10.1111/j.1432-1033.1976.tb10973.x] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
The mechanism of collagen glucosyltransferase reaction was studied with enzyme preparations purified about 2500-5000-fold from extract of homogenate of whole chick embryos. Data obtained in experiments on initial velocity and inhibition kinetics of the reaction were consistent with an ordered mechanism in which the substrates are bound to the enzyme in the following order: Mn2+, UDP-glucose and collagen substrate, the addition of Mn2+ being at thermodynamic equilibrium and the binding site of the UDP-glucose to the enzyme not being the same as that for Mn2+ and collagen substrate. Only one metal co-factor seems to be involved in the reaction. The collagen substrate can probably also react in some conditions with enzyme-Mn2+ and with enzyme-Mn2+-UDP, and the UDP with the free enzyme, but in all these instances dead-end complexes are formed. Evidence is presented for an ordered release of the products in the following order: glucosylated collagen, UDP and Mn2+, in which Mn2+ need not leave the enzyme during each catalytic cycle.
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