Linked Life Data

3052580

Source:http://linkedlifedata.com/resource/pubmed/id/3052580

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
15
pubmed:dateCreated
1988-12-22
pubmed:abstractText
31P NMR measurements were made (at 121.5 MHz and 5 degrees C) on enzyme-bound substrate complexes of 3-phosphoglycerate kinase in order to address three questions pertaining to (i) the integrity of the enzyme-substrate complexes with Mg(II) in the presence of sulfate concentrations typical of those used for crystallization in X-ray studies, (ii) the relative affinities of Mg(II) to ATP bound at the two sites on the enzyme, and (iii) the pH behavior of the different phosphate groups in the enzyme complexes. 31P chemical shift and spin-spin coupling constant changes showed that at concentrations of 0.5 M and higher, sulfate ion interferes with Mg(II) chelation to ATP and ADP free in solution as well as in their enzyme-bound complexes. The effect on enzyme complexes is stronger for the E.MgATP complex than for the E.MgADP complex. Sulfate ion (50 mM) also causes a approximately 0.5 ppm upfield chemical shift of the 31P resonance of enzyme-bound 3-P-glycerate even in the absence of ATP or Mg(II). A quantitative estimate of the dispartate affinities of Mg(II) to ATP bound at the two sites on the enzyme was made on the basis of computer simulation of changes in the line shape of beta-P (ATP) resonance and of changes in 31P chemical shift of the corresponding gamma-P (ATP) in the E.ATP complex with increasing [Mg(II)]. The concentrations of the relevant species that contribute to these 31P NMR signals were computed by assuming independent binding at the two sites.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
26
pubmed:volume
27
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
5574-8
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
31P NMR studies of enzyme-bound substrate complexes of yeast 3-phosphoglycerate kinase. 1. Effects of sulfate and pH. Mg(II) affinity at the two ATP sites.
pubmed:affiliation
Department of Physics, Indiana University, Purdue University, Indianapolis, Indiana 46223.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S.