Linked Life Data

2148688

Source:http://linkedlifedata.com/resource/pubmed/id/2148688

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
42
pubmed:dateCreated
1991-2-27
pubmed:abstractText
A family of mutants of the P22 bacteriophage tailspike protein has been characterized as temperature sensitive for folding (tsf) by King and co-workers [King, J. (1986) Bio/Technology 4, 297-303]. There is substantial evidence that the tsf mutations alter the folding pathway but not the stability of the final folded protein. Several point mutations are known to cause the tsf phenotype; most of these occur in regions of the tailspike sequence likely to take up reverse turns. Hence, it has been hypothesized that the correct folding of the P22 tailspike protein requires formation of turns and that the mutations causing tsf phenotypes interfere at this critical stage. We have tested this hypothesis by study of isolated peptides corresponding to a region of the P22 tailspike harboring a tsf mutation. Comparison of the tendencies of wild-type and tsf sequences to adopt turn conformations was achieved by the synthesis of peptides with flanking cysteine residues and the use of a thiol-disulfide exchange assay. We find that the wild-type sequence, either as a decapeptide (Ac-CVKFPGIETC-CONH2) or as a dodecapeptide (Ac-CYVKFPGIETLC-CONH2), has a 3-5-fold greater tendency for its termini to approach closely enough to form the intramolecular disulfide than do the peptide sequences corresponding to the tsf mutant sequences, which have a Gly----Arg substitution (Ac-CVKFPRIETC-CONH2 or Ac-CYVKFPRIETLC-CONH2). A peptide with a D-Arg substituted for the Gly has a slightly higher turn propensity than does the wild type. Together with data from nuclear magnetic resonance analysis of the oxidized peptides, this suggests that a type II beta turn is favored by the wild-type sequence. Our results on isolated peptides from the P22 tailspike protein support the model for its folding that includes reverse turn formation as a critical step.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0006-2960
pubmed:author
pubmed:issnType
Print
pubmed:day
23
pubmed:volume
29
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9765-71
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Reduced tendency to form a beta turn in peptides from the P22 tailspike protein correlates with a temperature-sensitive folding defect.
pubmed:affiliation
Department of Biochemistry, University of Texas Southwestern Medical Center, Dallas 75235-9041.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't