Microvilli isolated from 13762 mammary ascites tumor cells contain a major calcium-sensitive protein (AMV-p35) that can be isolated with microvillar microfilament cores prepared by Triton X-100 extraction in the presence but not abscence of calcium. AMV-p35 can be readily purified from ethylene glycol bis(β-aminoethyl ether)-N,N,N',N'-tetraacetic acid extracts of the microfilament cores by chromatography on an anion exchange column, to which it does not bind. Immunoblot analysis indicates that AMV-p35 is related to calpactin I, the pp60(src) tyrosine kinase substrate. In the presence of calcium, AMV-p35 binds approximately 4 mol of chlorpromazine per mole of protein in a binding process showing apparent positive cooperativity, similar to calmodulin; however, in contrast to calmodulin, AMV-p35 also binds phenothiazine in the abscence of calcium.
|Original language||English (US)|
|Number of pages||5|
|State||Published - 1987|
ASJC Scopus subject areas
- Agricultural and Biological Sciences (miscellaneous)
- Biochemistry, Genetics and Molecular Biology(all)
- Cell Biology