Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
22
|
pubmed:dateCreated |
1997-6-27
|
pubmed:databankReference | |
pubmed:abstractText |
The human blood group A and B glycosyltransferase enzymes are highly homologous and the alteration of four critical amino acid residues (Arg-176 --> Gly, Gly-235 --> Ser, Leu-266 --> Met, and Gly-268 --> Ala) is sufficient to change the enzyme specificity from a blood group A to a blood group B glycosyltransferase. To carry out a systematic study, a synthetic gene strategy was employed to obtain their genes and to allow facile mutagenesis. Soluble forms of a recombinant glycosyltransferase A and a set of hybrid glycosyltransferase A and B mutants were expressed in Escherichia coli in high yields, which allowed them to be kinetically characterized extensively for the first time. A functional hybrid A/B mutant enzyme was able to catalyze both A and B reactions, with the kcat being 5-fold higher for the A donor. Surprisingly, even a single amino acid replacement in glycosyltransferase A with the corresponding residue from glycosyltransferase B (Arg-176 --> Gly) produced enzymes with glycosyltransferase A activity only, but with very large (11-fold) increases in the kcat and increased specificity. The increases observed in kcat are among the largest obtained for a single amino acid change and are advantageous for the preparative scale synthesis of blood group antigens.
|
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/ABO Blood-Group System,
http://linkedlifedata.com/resource/pubmed/chemical/Amino Acids,
http://linkedlifedata.com/resource/pubmed/chemical/Galactosyltransferases,
http://linkedlifedata.com/resource/pubmed/chemical/N-Acetylgalactosaminyltransferases,
http://linkedlifedata.com/resource/pubmed/chemical/Recombinant Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/UDPgalactosamine-galactose...,
http://linkedlifedata.com/resource/pubmed/chemical/blood-group-substance...
|
pubmed:status |
MEDLINE
|
pubmed:month |
May
|
pubmed:issn |
0021-9258
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:day |
30
|
pubmed:volume |
272
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
14133-8
|
pubmed:dateRevised |
2006-11-15
|
pubmed:meshHeading |
pubmed-meshheading:9162041-ABO Blood-Group System,
pubmed-meshheading:9162041-Amino Acid Sequence,
pubmed-meshheading:9162041-Amino Acids,
pubmed-meshheading:9162041-Base Sequence,
pubmed-meshheading:9162041-Galactosyltransferases,
pubmed-meshheading:9162041-Humans,
pubmed-meshheading:9162041-Molecular Sequence Data,
pubmed-meshheading:9162041-Mutation,
pubmed-meshheading:9162041-N-Acetylgalactosaminyltransferases,
pubmed-meshheading:9162041-Recombinant Proteins,
pubmed-meshheading:9162041-Sequence Analysis, DNA,
pubmed-meshheading:9162041-Substrate Specificity
|
pubmed:year |
1997
|
pubmed:articleTitle |
Sequential interchange of four amino acids from blood group B to blood group A glycosyltransferase boosts catalytic activity and progressively modifies substrate recognition in human recombinant enzymes.
|
pubmed:affiliation |
Institute for Biological Sciences, National Research Council of Canada, Ottawa, Ontario, Canada K1A 0R6. nina.seto@nrc.ca
|
pubmed:publicationType |
Journal Article,
Research Support, Non-U.S. Gov't
|