Linked Life Data

8476931

Source:http://linkedlifedata.com/resource/pubmed/id/8476931

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-5-21
pubmed:abstractText
Ligand binding to the wild-type and a series of mutant porcine myoglobins, expressed and purified from Escherichia coli cells, has been studied using UV-VIS absorption spectroscopy. The proximal pocket mutation, F7 Ser-->Leu (F7), causes an increased affinity for OH- and N3- binding to metmyoglobin. A hydrogen bond between the F7 serine residue and the imidazole side-chain of the proximal histidine has been removed by this mutation. It is suggested that this allows the imidazole group to reorientate, reducing the steric clash between itself and the haem pyrrole nitrogen atoms and leading to a shortening of the bond between the proximal histidine and the haem iron. Other conformational changes further away from the haem pocket have also been induced, but the mutant still crystallizes under the same conditions as for the wild-type protein. A series of distal pocket mutants, E11 Val-->Thr (VT), E7 His-->Val (HV) and a mutant with both of these substitutions (M2) all have greatly reduced the OH- and N3- binding affinity. These effects have been interpreted by considering several factors: the changed stability of the aquometmyoglobin form, hydrogen-bond formation between the ligand and the E7 residue, and electrostatic repulsion between the ligand and the E11 threonine residue.
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
21
pubmed:volume
1163
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
67-74
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1993
pubmed:articleTitle
Ligand affinities in mutant metmyoglobins.
pubmed:affiliation
Department of Chemistry, University of York, UK.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't