Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1995-5-30
pubmed:abstractText
The glucose 1-phosphate (Glc-1-P) analog alpha-D-glucose 1-methylenephosphonate (Glc-1-MeP) inhibits competitively Escherichia coli maltodextrin phosphorylases against Glc-1-P (Ki = 0.20 mM) but also Pi (Ki = 0.36 mM). Exchange of the active site residue Glu637 to Asp by site-directed mutagenesis abolishes inhibition only in the synthesis direction (S-mode), while the degradative direction (P-mode) was not affected. Structural and conformational differences of the S-mode versus P-mode were also revealed by 31P-NMR spectroscopy by comparing chemical shifts of the cofactor pyridoxal-P in binary complexes formed either in the presence of Glc-1-MeP or of arsenate. In contrast the apparent pK of pyridoxal-P in both binary complexes was closely similar. Again, the total chemical shift of pyridoxal-P in the synthesis mode respectively degradative mode was differently affected in the binary complexes of the Glu637Asp mutant enzyme. This supports the contention that differential binding of the substrates in the synthesis or the degradative mode changes the arrangement and mutual interactions of cofactor phosphate and substrate phosphates.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
13
pubmed:volume
1243
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
381-5
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
A study of binary complexes of Escherichia coli maltodextrin phosphorylase: alpha-D-glucose 1-methylenephosphonate as a probe of pyridoxal 5'-phosphate-substrate interactions.
pubmed:affiliation
Theodor-Boveri-Institut für Biowissenschaften (Biozentrum), Universität Würzburg, Germany.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't