Purification and characterization of acid urease fromLactobacillus fermentum

✍ Scribed by Shigeya Kakimoto; Yasuhiro Sumino; Kenji Kawahara; Eiichirou Yamazaki; Isamu Nakatsui

• Book ID: 104651455
• Publisher: Springer
• Year: 1990
• Tongue: English
• Weight: 609 KB
• Volume: 32
• Category: Article
• ISSN: 1432-0614
• DOI: 10.1007/bf00173724

✦ Synopsis

Acid urease was purified to an electrophoretically homogeneous state, and the molecular weight was estimated to be 220 000. The enzyme consisted of three kinds of subunits, designated a, fl and 7z, with molecular weights of 67000, 16800 and 8600, respectively, in a (al f127q)2 structure. The isoelectric point of the enzyme was 4.8. The nickel content was found to be 1.9 atoms of nickel per a~f127q unit. The amino acid profile was different from those of known bacterial neutral ureases. The enzyme was most active at pH 2 and around 65 ° C. It was stable between pH 3 and 9, and below 50 ° C. The K,, for urea was 2.7 mM at pH 2. The enzyme activity was inhibited by Ag +, Hg 2+, Cu 2 +, p-chloromercuribenzoate and acetohydroxamate. The enzyme was separated into three subunits by reverse phase HPLC. The amino terminal amino acid sequences of the subunits a, fl and ), were Ser-Phe-Asp-Met-, Met-Val-Pro-Gly-and Met-Arg-Leu-Thr-, respectively.