Purification of a novel serpin-like protein from bovine brain.
We purified a novel serine proteinase inhibitor (serpin)-like protein from the bovine brain and named it B-43 from its molecular mass, 43 kDa. A cleaved peptide from B-43 was copurified with the native B-43. Partial amino acid sequencing of the purified B-43 showed that this protein was homologous to glia-derived nexin/protease nexin-1 (GDN/PN-1), plasminogen activator inhibitor 2, leukocyte elastase inhibitor (LEI) and placental thrombin inhibitor (PTI) among the serpins. Although B-43 had a similar amino acid composition to these serpins, the biochemical features of B-43 were different from them. B-43 did not form sodium dodecyl sulfate (SDS)-resistant serpin-proteinase complexes with thrombin, urokinase, pancreatic elastase and plasmin, suggesting that these proteinases were not the targets of B-43. In contrast to GDN/PN-1, B-43 did not have an affinity for heparin. B-43, having different biochemical properties from GDN/PN-1, appears to be an additional serpin expressed in the brain.
Nishibori
M
M
Department of Pharmacology, Okayama University Medical School, Japan.
Chikai
T
T
Kawabata
M
M
Ohta
J
J
Ubuka
T
T
Saeki
K
K
D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor; D000818:Animals; D001921:Brain / Q000201:enzymology; D001923:Brain Chemistry / Q000502:physiology*; D002352:Carrier Proteins / Q000378:metabolism; D002417:Cattle; D007120:Immunochemistry; D008969:Molecular Sequence Data; D008970:Molecular Weight; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D015842:Serine Proteinase Inhibitors / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D015843:Serpins / Q000032:analysis / Q000302:isolation & purification* / Q000378:metabolism; D013482:Superoxide Dismutase / Q000302:isolation & purification
D016564:Amyloid beta-Protein Precursor; D002352:Carrier Proteins; D058255:Protease Nexins; D011956:Receptors, Cell Surface; D015842:Serine Proteinase Inhibitors; D015843:Serpins; D013482:Superoxide Dismutase