Catalytic properties of a mutant β-galactosidase fromXanthomonas manihotisengineered to synthesize galactosyl-thio-β-1,3 and -β-1,4-glycosides
| Autor: | Stephen G. Withers, Hong-Ming Chen, Jin Hyo Kim, Young-Wan Kim |
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| Rok vydání: | 2006 |
| Předmět: |
Azides
Glycosylation Xanthomonas Stereochemistry Mutant Biophysics Glutamic Acid 010402 general chemistry 01 natural sciences Biochemistry Catalysis Ligases Bacterial Proteins Galactosides Structural Biology Genetics Glycoside hydrolase Glycoside hydrolase family 35 Glycosyl donor Molecular Biology chemistry.chemical_classification 010405 organic chemistry Glycosyl acceptor Glycoside Glycosidic bond Cell Biology Xanthomonas manihotis β-galactosidase beta-Galactosidase 0104 chemical sciences Kinetics Amino Acid Substitution chemistry Thioglycosides Glycoside hydrolase Family 35 Thioglycoligase Mutation Acid/base catalyst |
| Zdroj: | FEBS Letters. 580:4377-4381 |
| ISSN: | 0014-5793 |
| DOI: | 10.1016/j.febslet.2006.06.095 |
| Popis: | The identity of the acid/base catalyst of the Family 35 beta-galactosidases from Xanthomonas manihotis (BgaX) has been confirmed as Glu184 by kinetic analysis of mutants modified at that position. The Glu184Ala mutant of BgaX is shown to function as an efficient thioglycoligase, which synthesises thiogalactosides with linkages to the 3 and 4 positions of glucosides and galactosides in high (80%) yields. Kinetic analysis of the thioglycoligase reveals glycosyl donor K(m) values of 1.5-21 microM and glycosyl acceptor K(m) values from 180 to 500 microM. This mutant should be a valuable catalyst for the synthesis of metabolically stable analogues of this important glycosidic linkage. |
| Databáze: | OpenAIRE |
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