Identification of a 68 kDa protein which copurifies with type‐1 protein phosphatase as albumin

FEBS Letters

Heilmeyer, Ludwig M.G.¹  Villa-Moruzzi, Emma¹  Meyer, Helmut E.¹ 

[1] Institut für Physiologische Chemie I, Ruhruniversität, 4630 Bochum, FRG

关键词: Protein phosphatase Phosphorylase phosphatase Glycogen metabolism (Muscle) Albumin Amino acid composition N-terminal sequence analysis;    BSA;    bovine serum albumin;    RSA;    rabbit serum albumin;    PITC;    phenylisothiocyanate;    FA;    protein kinase that activates type-1 phosphatase;    DTT;    dithiothreitol;   

DOI  :  10.1016/0014-5793(86)80647-0

学科分类：生物化学/生物物理

来源: John Wiley & Sons Ltd.

【 摘 要 】

Proteins of 60–70 kDa copurify with some preparations of type-1 or type-2 phosphatases. In our system chromatography on polylysine-Affi-Gel 10 separates a 68 kDa protein from rabbit muscle glycogen particle phosphorylase phosphatase. The separation affects neither the activity nor the size of the phosphatase. The 68 kDa protein, although pure by SDS gel electrophoresis criteria, still displays phosphatase activity of approx. 6–8 . However, rechromatography either on Bio-Gel A-0.5 m or on Blue Sepharose CL-6B followed by gel filtration shows that the activity is due to a contamination with phosphatases of type 1 and type 2, displaying a molecular mass of 35 kDa, which can be totally removed from the 68 kDa protein. The amino acid composition of the 68 kDa protein is identical to that of rabbit serum albumin, within the limits of variation of the method. Furthermore, the sequence of the 38 N-terminal amino acids is the same in the isolated 68 kDa protein and in rabbit serum albumin.

【 授权许可】

Unknown