scholarly journals Core Glycosylation of Collagen Is Initiated by Two β(1-O)Galactosyltransferases

2008 ◽  
Vol 29 (4) ◽  
pp. 943-952 ◽  
Author(s):  
Belinda Schegg ◽  
Andreas J. Hülsmeier ◽  
Christoph Rutschmann ◽  
Charlotte Maag ◽  
Thierry Hennet
Keyword(s):  
Biological Significance ◽  
Protein Sequencing ◽  
Helix Formation ◽  
Left Handed ◽  
Hydroxy Proline ◽  
Mannose Binding ◽  
Triple Helix Formation ◽  
Lysine Residues ◽  
Low Levels ◽  
Binding Lectin

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 β(1-O)galactosyl- and α(1-2)glucosyltransferase enzymes. We have identified two collagen galactosyltransferases using affinity chromatography and tandem mass spectrometry protein sequencing. The two collagen β(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.

Low levels of mannose-binding lectin confers protection against tuberculosis in Turkish children

2008 ◽  
Vol 27 (12) ◽  
pp. 1165-1169 ◽  
Author(s):  
H. Cosar ◽  
F. Ozkinay ◽  
H. Onay ◽  
N. Bayram ◽  
A. R. Bakiler ◽  
...  
Keyword(s):  
Mannose Binding Lectin ◽  
Turkish Children ◽  
Mannose Binding ◽  
Low Levels ◽  
Binding Lectin

Mannose-binding lectin gene (MBL2) polymorphisms related to the mannose-binding lectin low levels are associated to dengue disease severity

2016 ◽  
Vol 77 (7) ◽  
pp. 571-575 ◽  
Author(s):  
Gabriela G. Figueiredo ◽  
Renata D. Cezar ◽  
Naishe M. Freire ◽  
Vanessa G. Teixeira ◽  
Paulo Baptista ◽  
...  
Keyword(s):  
Disease Severity ◽  
Mannose Binding Lectin ◽  
Dengue Disease ◽  
Lectin Gene ◽  
Mannose Binding ◽  
Low Levels ◽  
Binding Lectin

scholarly journals Mannose-Binding Lectin Binds to a Range of Clinically Relevant Microorganisms and Promotes Complement Deposition

2000 ◽  
Vol 68 (2) ◽  
pp. 688-693 ◽  
Author(s):  
Olaf Neth ◽  
Dominic L. Jack ◽  
Alister W. Dodds ◽  
Helen Holzel ◽  
Nigel J. Klein ◽  
...  
Keyword(s):  
Immune Defense ◽  
Mannose Binding Lectin ◽  
Dependent Manner ◽  
Group B Streptococci ◽  
Concentration Dependent Manner ◽  
Mannose Binding ◽  
Low Levels ◽  
Serum Lectin ◽  
Group B ◽  
Binding Lectin

ABSTRACT Mannose-binding lectin (MBL) is a collagenous serum lectin believed to be of importance in innate immunity. Genetically determined low levels of the protein are known to predispose to infections. In this study the binding of purified MBL to pathogens isolated from immunocompromised children was investigated by flow cytometry. DiverseCandida species, Aspergillus fumigatus,Staphylococcus aureus, and beta-hemolytic group A streptococci exhibited strong binding of MBL, whereas Escherichia coli, Klebsiella species, and Haemophilus influenzae type b were characterized by heterogeneous binding patterns. In contrast, beta-hemolytic group B streptococci,Streptococcus pneumoniae, and Staphylococcus epidermidis showed low levels of binding. Bound MBL was able to promote C4 deposition in a concentration-dependent manner. We conclude that MBL may be of importance in first-line immune defense against several important pathogens.

Purification, characterization and biological significance of mannose binding lectin from Dioscorea bulbifera bulbils

2017 ◽  
Vol 102 ◽  
pp. 1146-1155 ◽  
Author(s):  
Mamta Sharma ◽  
Vishwanathreddy Hotpet ◽  
Sindhura B.R. ◽  
Kamalanathan A.S. ◽  
Bale M. Swamy ◽  
...  
Keyword(s):  
Biological Significance ◽  
Mannose Binding Lectin ◽  
Mannose Binding ◽  
Dioscorea Bulbifera ◽  
Binding Lectin

scholarly journals Further studies on the effect of the collagen triple-helix formation on the hydroxylation of lysine and the glycosylations of hydroxylysine in chick-embryo tendon and cartilage cells

1977 ◽  
Vol 166 (3) ◽  
pp. 357-362 ◽  
Author(s):  
Aarne Oikarinen ◽  
Henrik Anttinen ◽  
Kari I. Kivirikko
Keyword(s):  
Chick Embryo ◽  
Triple Helix ◽  
Collagen Triple Helix ◽  
Helix Formation ◽  
Tendon Cells ◽  
Triple Helix Formation ◽  
Lysine Residues ◽  
Cartilage Cells ◽  
Helical Molecules ◽  
And Cartilage

The hydroxylation of lysine and glycosylations of hydroxylysine were studied in isolated chick-embryo tendon and cartilage cells under conditions in which collagen triple-helix formation was either inhibited or accelerated. The former situation was obtained by incubating the tendon cells with 0.6mm-dithiothreitol, thus decreasing their proline hydroxylase activity by about 99%. After labelling with [14C]proline, the formation of hydroxy[14C]proline was found to have declined by about 95%. Since the hydroxylation of a relatively large number of proline residues is required for triple-helix formation at 37°C, the pro-α-chains synthesized under these conditions apparently cannot form triple-helical molecules. Labelling experiments with [14C]lysine indicated that the degree of hydroxylation of the lysine residues in the collagen synthesized was slightly increased and the degree of the glycosylations of the hydroxylysine residues more than doubled, the largest increase being in the content of glucosylgalactosylhydroxylysine. Recovery of chick-embryo cartilage cells from temporary anoxia was used to obtain accelerated triple-helix formation. A marked decrease was found in the extent of hydroxylation of the lysine residues in the collagen synthesized under these conditions, and an even larger decrease occurred in the glycosylations of the hydroxylysine residues. The results support the previous suggestion that the triple-helix formation of the pro-α-chains prevents further hydroxylation of lysine residues and glycosylations of hydroxylysine residues during collagen biosynthesis.

Sign in / Sign up

Export Citation Format

Share Document