Molecular cloning, characterisation and molecular modelling of two novel T-synthases from mollusc origin

Abstract The glycoprotein-N-acetylgalactosamine β1,3-galactosyltransferase, known as T-synthase (EC 2.4.1.122), plays a crucial role in the synthesis of the T-antigen, which is the core 1 O-glycan structure. This enzyme transfers galactose from UDP-Gal to GalNAc-Ser/Thr. The T-antigen has significan...

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Bibliographic Details
Published in:Glycobiology
Main Authors: Zemkollari, Marilica, Oostenbrink, Chris, Grabherr, Reingard, Staudacher, Erika
Other Authors: Austrian Science Fund
Format: Article in Journal/Newspaper
Language:English
Published: Oxford University Press (OUP) 2024
Subjects:
Online Access:http://dx.doi.org/10.1093/glycob/cwae013
https://academic.oup.com/glycob/advance-article-pdf/doi/10.1093/glycob/cwae013/56879146/cwae013.pdf
https://academic.oup.com/glycob/article-pdf/34/4/cwae013/57193872/cwae013.pdf
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Summary:Abstract The glycoprotein-N-acetylgalactosamine β1,3-galactosyltransferase, known as T-synthase (EC 2.4.1.122), plays a crucial role in the synthesis of the T-antigen, which is the core 1 O-glycan structure. This enzyme transfers galactose from UDP-Gal to GalNAc-Ser/Thr. The T-antigen has significant functions in animal development, immune response, and recognition processes. Molluscs are a successful group of animals that inhabit various environments, such as freshwater, marine, and terrestrial habitats. They serve important roles in ecosystems as filter feeders and decomposers but can also be pests in agriculture and intermediate hosts for human and cattle parasites. The identification and characterization of novel carbohydrate active enzymes, such as T-synthase, can aid in the understanding of molluscan glycosylation abilities and their adaptation and survival abilities. Here, the T-synthase enzymes from the snail Pomacea canaliculata and the oyster Crassostrea gigas are identified, cloned, expressed, and characterized, with a focus on structural elucidation. The synthesized enzymes display core 1 β1,3-galactosyltransferase activity using pNP-α-GalNAc as substrate and exhibit similar biochemical parameters as previously characterised T-synthases from other species. While the enzyme from C. gigas shares the same structural parameters with the other enzymes characterised so far, the T-synthase from P. canaliculata lacks the consensus sequence CCSD, which was previously considered indispensable.