title: Isolation and characterization of a serine proteinase, inactivating m-subunit of lactate dehydrogenase, from Penicillium citrinum KE-1.
abstract: A selective inactivating enzyme for the m-subunit of lactate dehydrogenase (LDH) was found in the culture filtrate of Penicillium citrinum KE-1, newly isolated from soil. The enzyme was purified from the culture filtrate by ammonium sulfate fractionation, column chromatography on CM-Sepharose CL-6B, and gel filtration on Sephadex G-100. The purification was 124-fold with an activity yield of 81%. The purified enzyme gave a single band, corresponding to a molecular weight of 32,000, on SDS polyacrylamide gel electrophoresis, and the isoelectric point was 9.5. The enzyme specifically inactivated the m-subunit of LDH but showed no activity on the h-subunit of LDH. The enzyme, named KE-1 proteinase, proved to be a serine-type proteinase. Limited proteolysis of native m-subunit of LDH was assumed to result in a loss of enzyme activity.
authors.affiliation: Research and Development Center, International Reagents Corporation, Kobe, Japan.
authors.forename: Y
authors.initials: Y
authors.lastname: Watazu
authors.forename: K
authors.initials: K
authors.lastname: Nagamatsu
authors.forename: Y
authors.initials: Y
authors.lastname: Shirahase
authors.forename: N
authors.initials: N
authors.lastname: Kaneda
authors.forename: S
authors.initials: S
authors.lastname: Murao
authors.forename: H
authors.initials: H
authors.lastname: Okabe
mesh_terms: D000595:Amino Acid Sequence; D002850:Chromatography, Gel; D002851:Chromatography, High Pressure Liquid; D003470:Culture Media; D004591:Electrophoresis, Polyacrylamide Gel; D006868:Hydrolysis; D007527:Isoenzymes; D007770:L-Lactate Dehydrogenase / Q000037:antagonists & inhibitors*; D008969:Molecular Sequence Data; D008970:Molecular Weight; D010084:Oxidation-Reduction; D010407:Penicillium / Q000201:enzymology*; D017386:Sequence Homology, Amino Acid; D012697:Serine Endopeptidases / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D015842:Serine Proteinase Inhibitors / Q000494:pharmacology; D013379:Substrate Specificity
chemical_list: D003470:Culture Media; D007527:Isoenzymes; D015842:Serine Proteinase Inhibitors; D007770:L-Lactate Dehydrogenase; D012697:Serine Endopeptidases