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Proteins and polypeptides of envelope membranes from spinach chloroplasts
Author(s) -
Nguyen Tan Duc,
Siegenthaler Paul-André
Publication year - 1983
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(83)80020-9
Subject(s) - calmodulin , egta , spinach , biochemistry , atpase , chloroplast , chemistry , affinity chromatography , isoelectric focusing , enzyme , isoelectric point , membrane , sepharose , chromatography , calcium , organic chemistry , gene
Spinach chloroplasts are known to contain calmodulin and to display an envelope‐bound ATPase activity. This activity, stimulated by 0.15 mM Ca 2+ and 5 mM Mg 2+ , is further enhanced by calmodulin. The apparent K m for ATP was 0.55 mM. The enzyme was especially sensitive to NH 4 VO 3 , SbCl 3 , LaCl 3 and oligomycin. An attempt to isolate the ATPase by calmodulin‐Sepharose affinity chromatography was successful. The EGTA‐eluted fraction contained 2 proteins out of the 21 proteins separated previously by isoelectric focussing [(1983) Biochim. Acta 722, 226—333] and exhibited an ATPase activity.