Ca(2+)-dependent and independent interactions of calretinin with hydrophobic resins.
The ability of rat calretinin to bind to hydrophobic resins in a Ca(2+)-dependent manner was examined. Both native calretinin present in cerebellum extract and purified recombinant calretinin bound similarly to hydrophobic resins such as phenyl-, hexyl-, octyl-, and W7-agarose. Hydrophobic interactions of calretinin were partially Ca(2+)-dependent since 1/3 of bound protein was released from the resins by EGTA under varied conditions. Some calretinin tryptic fragments bound to octyl-agarose in a manner similar to uncleaved calretinin, while others bound to the resin in a Ca(2+)-independent manner. These and other results suggest that calretinin has several hydrophobic regions of varied strength and sensitivity to Ca2+. It is proposed that the local changes in hydrophobicity induced by Ca2+ binding might be relevant for calretinin functions.
Kuźnicki
J
J
Laboratory of Clinical Science, National Institute of Mental Health, Bethesda, Maryland 20892.
Winsky
L
L
Jacobowitz
D M
DM
D000818:Animals; D064032:Calbindin 2; D002118:Calcium / Q000502:physiology*; D002531:Cerebellum / Q000737:chemistry; D055598:Chemical Phenomena; D002627:Chemistry, Physical; D004533:Egtazic Acid / Q000494:pharmacology; D011485:Protein Binding; D051381:Rats; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D012116:Resins, Plant / Q000378:metabolism*; D064030:S100 Calcium Binding Protein G / Q000302:isolation & purification / Q000378:metabolism*
C576512:Calb2 protein, rat; D064032:Calbindin 2; D011993:Recombinant Fusion Proteins; D012116:Resins, Plant; D064030:S100 Calcium Binding Protein G; D004533:Egtazic Acid; D002118:Calcium