Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
41
pubmed:dateCreated
1991-11-20
pubmed:abstractText
The cardiac and skeletal TnI inhibitory regions have identical sequences except at position 110 which contains Pro in the skeletal sequence and Thr in the cardiac sequence. The effect of the synthetic TnI inhibitory peptides [skeletal TnI peptide (104-115), cardiac TnI peptide (137-148), and a single Gly-substituted analogue at position 110] on the secondary structure of skeletal and cardiac TnC was investigated. The biphasic increases in ellipticity and tyrosine fluorescence were analyzed to determine the Ca2+ binding constants for the high- and low-affinity Ca2+ binding sites of TnC. Importantly, the skeletal and cardiac TnI peptides altered Ca2+ binding at the low-affinity sites of TnC, but the magnitude and direction of the pCa shifts depended on whether the peptides were bound to skeletal or cardiac TnC. For example, binding of skeletal TnI peptide to skeletal TnC (monitored by CD) caused a pCa shift of +0.30 unit such that a lower Ca2+ concentration was required to fill sites I and II, while binding of this peptide to cardiac TnC caused a pCa shift of -0.35 unit such that a higher Ca2+ concentration was required to fill site II. This is the first report of the alteration at the low-affinity regulatory sites (located in the N-terminal domain) by the skeletal TnI inhibitory peptide, even though the primary peptide binding site is located in the C-terminal domain of TnC, a finding which strongly indicates that there is communication between the two halves of the TnC molecule.(ABSTRACT TRUNCATED AT 250 WORDS)
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
15
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
9974-81
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
A comparative study of the interactions of synthetic peptides of the skeletal and cardiac troponin I inhibitory region with skeletal and cardiac troponin C.
pubmed:affiliation
Department of Biochemistry, University of Alberta, Edmonton, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't