R. Lecocq et al., RAPID PURIFICATION AND IDENTIFICATION OF CALCYPHOSINE, A CA2-BINDING PROTEIN PHOSPHORYLATED BY PROTEIN KINASE-A(), Biochemical journal, 306, 1995, pp. 147-151
A method is presented for the rapid purification of dog thyroid calcyp
hosine, a protein previously identified as a major substrate for cycli
c AMP-dependent protein kinase in dog thyroid slices stimulated by thy
rotropin [Lecocq, Lamy and Dumont (1979) Eur. J Biochem 102, 147-152].
The protein was previously identified as a spot on two-dimensional ge
ls and is now purified in its native form by a procedure involving thr
ee chromatographic steps. Homogeneous calcyphosine identified by SDS/P
AGE, immunoblotting and peptide sequencing can be obtained within 7 h.
As for calmodulin, Ca2+-dependent conformational changes can be shown
by Ca2+-dependent hydrophobic interaction chromatography using phenyl
-Sepharose. Unlike calmodulin, calcyphosine is a substrate for protein
kinase A.