Linked Life Data

8720125

Source:http://linkedlifedata.com/resource/pubmed/id/8720125

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1996-10-10
pubmed:abstractText
The properties of sulfhydryl (SH) and disulfide (S-S) groups in Bacillus cereus BQ10-S1 Spo III beta-amylase have been investigated to clarify their roles in the enzyme action. Two out of three cysteine residues in B. cereus beta-amylase were found to form an S-S bond, which was found to be located between Cys91 and Cys99 by the analysis of an S-S containing peptide. The replacement of the soybean beta-amylase model around L3 loop 1 revealed that the S-S bond is located at the root of this flexible loop that moves between open and closed forms during catalysis. The analysis of fluorescence labeled peptides revealed that the remaining free SH group was Cys331. Modification of Cys331 with N-ethylmaleimide or p-chloromercuribenzoic acid (PCMB) caused inactivation of the enzyme. The rate constants for the reactions were consistent with those of Cys343 in soybean enzyme. The binding affinity of the PCMB-modified enzyme to maltose was also decreased. These results indicate that the modification of Cys331, which exists as a free SH group in B. cereus beta-amylase caused inactivation by a similar mechanism to that in the case of Cys343 in soybean beta-amylase as assumed from the sequence homology. This cysteine residue has a common role in beta-amylases irrespective their origin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0021-924X
pubmed:author
pubmed:issnType
Print
pubmed:volume
118
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1124-30
pubmed:dateRevised
2007-12-19
pubmed:meshHeading
pubmed:year
1995
pubmed:articleTitle
The role of SH and S-S groups in Bacillus cereus beta-amylase.
pubmed:affiliation
Research Institute for Food Science, Kyoto University.
pubmed:publicationType
Journal Article, Comparative Study