A new alkaline serine protease from alkalophilicBacillussp.: Cloning, sequencing, and characterization of an intracellular protease

✍ Scribed by Youhei Yamagata; Eiji Ichishima

• Publisher: Springer
• Year: 1995
• Tongue: English
• Weight: 848 KB
• Volume: 30
• Category: Article
• ISSN: 0343-8651
• DOI: 10.1007/bf00369863

✦ Synopsis

To obtain a new serine protease from alkalophilic Bacillus sp. NKS-21, shotgun cloning was carried out. As a result, a new protease gene was obtained. It encoded an intracellular serine protease (ISP-1) in which there was no signal sequence. The molecular weight was 34,624. The protease showed about 50% homology with those of intracellular serine proteases (ISP-1) from Bacillus subtilis, B. polymyxa, and alkatophilic Bacillus sp. No. 221. The amino acid residues that form the catalytic triad, Ser, His and Asp, were completely conserved in comparison with subtilisins (the extracellular proteases from Bacillus). The cloned intracellular protease was expressed iLn Escherichia coli, and its purification and characterization were carried out. The enzyme showed stability under alkaline condition at pH 10 and tolerance to surfactants. The cloned ISP-1 digested well nucleoproteins, clupein and salmin, for the substrates.