Purification and some properties of a thermostable metal proteinase produced by Thermomicrobium sp. KN-22 strain.
An extreme thermophile that produces a heat-stable proteinase was isolated from hot-spring water and classified as Thermomicrobium sp. KN-22 (growth temperature, 50-83 degrees C; and optimum growth temperature, 70 degrees C). The proteinase was purified from the culture broth of this strain by fractionation with ammonium sulfate, chromatography on columns of DEAE-cellulose and CM-Sepharose CL-6B, and HPLC on TSKgel CM-5PW. The purified enzyme gave a single band on SDS-polyacrylamide gel electrophoresis and a single peak after HPLC (yield 8.8%). The enzyme had maximum activity at pH 8.5 and at 75 degrees C and it was stable up to 60 degrees C. The molecular weight of the enzyme was 35,000 by SDS-PAGE. Since the enzymatic activity was completely inhibited by EDTA, o-phenanthroline, and phosphoramidon, it appears that the enzyme is a metal proteinase.
Department of Applied Microbial Technology, Kumamoto Institute of Technology, Japan.
S
S
Murao
Y
Y
Nomura
K
K
Nagamatsu
K
K
Hirayama
M
M
Iwahara
T
T
Shin
D000595:Amino Acid Sequence; D004795:Enzyme Stability; D006088:Gram-Negative Aerobic Bacteria / Q000201:enzymology* / Q000302:isolation & purification; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D006868:Hydrolysis; D007328:Insulin / Q000378:metabolism; D008666:Metalloendopeptidases / Q000187:drug effects / Q000302:isolation & purification* / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D013696:Temperature
D007328:Insulin; D008666:Metalloendopeptidases