Structural and functional characterization of calelectrins from bovine liver.
Two Ca2(+)-dependent membrane-binding proteins with apparent molecular weights of 70000 (calelectrin70) and 32000 (calelectrin32) were isolated from bovine liver using phenyl-Sepharose affinity chromatography followed by diethylaminoethyl (DEAE)-cellulose and Ultrogel AcA44 chromatographies. Limited proteolysis and immunological analyses indicated that calelectrin32 was not a digested product from calelectrin70. Both calelectrins bound to phosphatidylserine and to calmodulin in a Ca2(+)-dependent manner. Circular dichroism studies showed that the apparent alpha-helical contents of calelectrin70 and calelectrin32 were 25 and 40%, respectively and they underwent Ca2(+)-dependent conformational changes. When the calelectrins were incubated with a brain microtubule preparation, they were phosphorylated by endogenous kinase(s) and phosphorylation occurred on serine residues. Moreover, calelectrin70 showed an inhibitory action on endogenous kinase activity in the presence of Ca2+.
Fujii
T
T
Faculty of Textile Science and Technology, Shinshu University, Nagano, Japan.
Akashi
H
H
Ogoma
Y
Y
Kondo
Y
Y
D000818:Animals; D017302:Annexins; D002135:Calcium-Binding Proteins / Q000032:analysis* / Q000378:metabolism; D002417:Cattle; D002942:Circular Dichroism; D008099:Liver / Q000737:chemistry*; D008970:Molecular Weight; D011485:Protein Binding
D017302:Annexins; D002135:Calcium-Binding Proteins