Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1995-6-29
pubmed:abstractText
A previous chemical modification study [Kitamura et al. (1989) J. Biol. Chem. 264, 6344-6438] has shown that N-bromoacetylethanolamine phosphate labeled specifically Cys107 of rat liver Fru 6-P,2-kinase:Fru 2.6-Pase and the corresponding Cys of the bovine heart enzyme, leading to inactivation of kinase activity. Since Fru 6-P provided protection against the inactivation, this region of the enzyme was thought to be a Fru 6-P binding site of the kinase enzyme. To examine this possibility, oligonucleotide-directed mutagenesis has been used to alter several residues in expressed rat testis Fru 6-P,2-kinase:Fru 2,6-Pase. The change of Lys100, Lys103, and Asp112 caused at most a 2-fold increase in KmF6P and a 2-3-fold increase in KmATP, suggesting that these residues are not involved in the direct binding of Fru 6-P. However, change of Arg102 to Leu and to Lys resulted in a 325x and 22x, respectively, increase in KmF6P, and change of Arg102 to Glu resulted in nearly complete loss of the kinase activity. Change of Cys105 to Ala or Ser increased KmF6P about 10x. The Vmax of all these mutated enzymes except the one that changed Arg102 to Glu (R102E) was increased 10% to 85%. The kinetic parameters of Fru 2,6-Pase were not altered by these changes. R102E formed several polymeric forms of the enzyme, including a tetramer. Both R102E and an additional derivative that substituted Lys for Arg102 (R102K) were slightly more susceptible to guanidine inactivation than the wild-type enzyme.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
16
pubmed:volume
34
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
6389-93
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed-meshheading:7756268-Amino Acid Sequence, pubmed-meshheading:7756268-Animals, pubmed-meshheading:7756268-Binding Sites, pubmed-meshheading:7756268-Cysteine, pubmed-meshheading:7756268-Guanidine, pubmed-meshheading:7756268-Guanidines, pubmed-meshheading:7756268-Hexosephosphates, pubmed-meshheading:7756268-Kinetics, pubmed-meshheading:7756268-Molecular Sequence Data, pubmed-meshheading:7756268-Multienzyme Complexes, pubmed-meshheading:7756268-Mutagenesis, Site-Directed, pubmed-meshheading:7756268-Phosphofructokinase-2, pubmed-meshheading:7756268-Phosphoric Monoester Hydrolases, pubmed-meshheading:7756268-Phosphotransferases, pubmed-meshheading:7756268-Protein Denaturation, pubmed-meshheading:7756268-Rats, pubmed-meshheading:7756268-Sequence Alignment, pubmed-meshheading:7756268-Sequence Homology, Amino Acid, pubmed-meshheading:7756268-Structure-Activity Relationship
pubmed:year
1995
pubmed:articleTitle
Hexose phosphate binding sites of fructose 6-phosphate,2-kinase:fructose 2,6-bisphosphatase.
pubmed:affiliation
Research Service, Department of Veterans Affairs Medical Center, Dallas, TX 75216, USA.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.