A serpin with M(r) 43,000 is a binding protein of M(r) 25,000 protein, a substrate for protein ser/thr kinase detected in Xenopus laevis oocytes.
In an attempt to get some clue as to the function of M(r) 25,000 protein, a protein Ser/Thr kinase substrate detected in Xenopus laevis oocytes [Hashimoto, E. et al. (1995) J. Biochem. 118, 453-460], the binding protein was surveyed using the (32)P-labeled protein by casein kinase II as a screening probe. When the cytosolic proteins from oocytes were transferred to a polyvinylidene fluoride membrane and incubated with the labeled protein, only one protein with M(r) 43,000 was visualized on autoradiography. This protein was purified to a nearly homogeneous state through several column chromatography steps. The amino acid sequence of the amino-terminal region of this protein identified it as a kind of serine protease inhibitor (serpin) [Holland, L.J. et al. (1992) J. Biol. Chem. 267, 7053-7059]. However, the M(r) 25,000 protein did not have any effect on the inhibitory action of this serpin on alpha-chymotrypsin. In addition, several binding proteins were also detected in the particulate fraction of oocytes, although the exact identity of these proteins is not clear at this time. These results suggest that the M(r) 25,000 protein may play some role(s) by interacting with these binding proteins in Xenopus oocytes.
Goto
N
N
Department of Pathological Biochemistry, School of Life Sciences, Faculty of Medicine, Tottori University, Nishicho, Yonago 683-8503, Japan.
Muto
S
S
Sugimoto
I
I
Ikawa-Kitayama
K
K
Igarashi
K
K
Ito
S
S
Hashimoto
E
E
D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism; D005260:Female; D066298:In Vitro Techniques; D009865:Oocytes / Q000201:enzymology*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011869:Radioligand Assay; D015842:Serine Proteinase Inhibitors / Q000737:chemistry / Q000378:metabolism; D015843:Serpins / Q000737:chemistry / Q000302:isolation & purification*; D013379:Substrate Specificity; D029867:Xenopus Proteins; D014982:Xenopus laevis / Q000378:metabolism
D002352:Carrier Proteins; D015842:Serine Proteinase Inhibitors; D015843:Serpins; D029867:Xenopus Proteins; C077804:SERPINA6 protein, Xenopus; D017346:Protein Serine-Threonine Kinases