Abstract
Crude enzyme extract was obtained from a low-pH soil from a tea field by shaking with 0.1 M PO4 3– buffer (pH 7.0). Hydrolytic activity toward benzyloxycarbonyl-L-Phe-L-Leu (Z-L-Phe-L-Leu) and Z-L-Phe-L-Tyr-L-Leu showed two pH optima, at about pH 5 and 9, suggesting that the soil contained at least two protease components. The acid-type protease in the extract was assumed to be Ser-carboxypeptidase because phenylmethanesulphonyl fluoride and diisopropylphosphoro fluoridate inhibited its activity. Peptide bonds in the C-terminal residues of Leu-enkephalin and angiotensin I were split more by protease than those in the N-terminal residue. The apparent molecular weight of the acid-type protease was estimated to be 75 kDa by Sephadex G-100 gel filtration and the isoelectric point 4.4 by isoelectric focusing. A neutral-type protease in the extract was assumed to be a metallocarboxypeptidase because only o-phenanthrorine inhibited its activity. Peptide bonds in the C-terminal residues of Leu-enkephalin and angiotensin I were hydrolyzed to a greater extent than those in the N-terminal residues. The apparent molecular weight of the neutral-type protease was estimated to be 37 kDa and the isoelectric point 5.8, 8.0 and 9.4. The isoelectric point 9.4 fraction showed the highest relative activity.
Article PDF
Similar content being viewed by others
Avoid common mistakes on your manuscript.
Author information
Authors and Affiliations
Additional information
Received: 12 January 1999 / Accepted: 22 June 1999
Rights and permissions
About this article
Cite this article
Kamimura, Y., Hayano, K. Properties of protease extracted from tea-field soil. Biol Fertil Soils 30, 351–355 (2000). https://doi.org/10.1007/s003740050015
Issue Date:
DOI: https://doi.org/10.1007/s003740050015