Linked Life Data

9162041

Source:http://linkedlifedata.com/resource/pubmed/id/9162041

Statements in which the resource exists as a subject.
PredicateObject
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
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: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