Linked Life Data

20971157

Source:http://linkedlifedata.com/resource/pubmed/id/20971157

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2011-1-11
pubmed:abstractText
Arsenic (+3 oxidation state) methyltransferase (AS3MT) catalyzes the methylation of inorganic arsenic (iAs) and plays important role in the detoxication of this metalloid. There are fourteen cysteine residues in the human AS3MT (hAS3MT), among which twelve are absolutely conserved; Cys334 and Cys360 are unique; Cys368 and Cys369 are identified as a CysCys pair. The roles of several conserved cysteine residues in rat AS3MT and hAS3MT have been reported. Herein, the other conserved cysteine residues (Cys72, Cys271, Cys375) and the unique ones (Cys334, Cys360) were systematically replaced by serine using site-directed mutagenesis to study their functions. The mutants were investigated for enzymatic activity, kinetics, thermal stability and secondary structures. Present results indicate that C72S is completely inactive in methylation of iAs and has distinct changes in the secondary structures; Cys72 might form a critical intramolecular disulfide bond with Cys250; Cys271 and Cys375 do not affect the activity and structure of the hAS3MT. However, the mutations of Cys334 and Cys360 can decrease the enzymatic turnovers and change the conformation of the hAS3MT. The kinetic data show that Cys271, Cys334, Cys360 and Cys375 are not involved in the SAM binding. Additionally, all these cysteine residues except Cys375 affect the thermotropic properties of the hAS3MT.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
1638-6183
pubmed:author
pubmed:copyrightInfo
Copyright © 2010 Elsevier Masson SAS. All rights reserved.
pubmed:issnType
Electronic
pubmed:volume
93
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
369-75
pubmed:meshHeading
pubmed:year
2011
pubmed:articleTitle
Functional and structural evaluation of cysteine residues in the human arsenic (+3 oxidation state) methyltransferase (hAS3MT).
pubmed:affiliation
State Key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Nanjing University, Hankou Road 22, Nanjing 210093, PR China.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't