Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
28
pubmed:dateCreated
1986-10-31
pubmed:abstractText
Tropomyosin isoforms of the low Mr class were isolated from chicken intestinal epithelium and brain, and their physical and functional properties were characterized. Tropomyosin from each tissue contains four distinct polypeptides, all of about 32,000 daltons. In two-dimensional gels, brain tropomyosin contains two major and two minor polypeptides; the major epithelium isoforms coelectrophorese with the two minor brain isoforms. Conversely, only small amounts of the major brain isoforms are detected in the epithelium. Actin-binding properties of brain tropomyosin isoforms are distinct from those of the intestinal epithelium. At 2.5 mM MgCl2 and physiological ionic strength, the intestinal epithelial tropomyosin binds to filamentous actin with an apparent Ka of 8 X 10(6) M-1 whereas brain tropomyosin has an apparent Ka of 8 X 10(5) M-1. Tropomyosin from either tissue binds actin cooperatively with a Hill coefficient of 2.3 for intestinal epithelial cell and 1.95 for brain tropomyosin. Isoforms from both tissues exhibit reduced head-to-tail polymerizability as compared to muscle tropomyosin. The actin-binding properties of intestinal epithelial cell tropomyosin are therefore similar to those of the muscle tropomyosins even though the isoforms have lower molecular weight, a paracrystal structure, and reduced head-to-tail polymerizability typical of the other nonmuscle tropomyosins. These results indicate that a heterogeneity of functional properties may be expressed among the low Mr tropomyosin isoforms.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13350-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1986
pubmed:articleTitle
Low Mr tropomyosin isoforms from chicken brain and intestinal epithelium have distinct actin-binding properties.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.