Linked Life Data

3125174

Source:http://linkedlifedata.com/resource/pubmed/id/3125174

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
7
pubmed:dateCreated
1988-4-6
pubmed:abstractText
Half-lives of Bacillus alpha-amylases at 90 degrees C and pH 6.5 greatly increase in the series from Bacillus amyloliquefaciens to Bacillus stearothermophilus to Bacillus licheniformis, e.g. the difference in thermostability between the first and the third enzymes exceeds 2 orders of magnitude. This stabilization is achieved by lowering the rate constant of monomolecular conformational scrambling, which is the cause of irreversible thermoinactivation of B. amyloliquefaciens and B. stearothermophilus alpha-amylases, so that for B. licheniformis alpha-amylase, another process, deamidation of Asn/Gln residues, emerges as the cause of inactivation. The extra thermostability of the thermophilic enzyme was found to be mainly due to additional salt bridges involving a few specific lysine residues (Lys-385 and Lys-88 and/or Lys-253). These stabilizing electrostatic interactions reduce the extent of unfolding of the enzyme molecule at high temperatures, consequently making it less prone to forming incorrect (scrambled) structures and thus decreasing the overall rate of irreversible thermoinactivation. The implications of these findings for protein engineering are discussed.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
3092-6
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Why is one Bacillus alpha-amylase more resistant against irreversible thermoinactivation than another?
pubmed:affiliation
Department of Applied Biological Sciences, Massachusetts Institute of Technology, Cambridge 02139.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, U.S. Gov't, Non-P.H.S.