ISSN:
1432-0789
Keywords:
Proteinases
;
Metalloproteinase
;
Soil enzyme
;
Soil extract
;
Nitrogen transformation
Source:
Springer Online Journal Archives 1860-2000
Topics:
Biology
,
Geosciences
,
Agriculture, Forestry, Horticulture, Fishery, Domestic Science, Nutrition
Notes:
Summary A metalloproteinase was found to be the main component of a protease in the extract from an Andosol collected from a tomato field. The protease has a pH optimum of 7 for benzyloxycarbonyl-L-phenylalanyl-L-tyrosyl-L-leucine with tyrosylleucine as the main reaction product. The Km value for the substrate was 0.4 mM. Activity was inhibited by EDTA but not by pepstatin, p-chloromercuribenzoate and phenylmethanesulfonyl fluoride. After the removal of EDTA from the inactivated enzyme by dialysis and the addition of metal ions (Zn2+, Mn2+ and Fe3+), the enzyme activity could be recovered. The apparent isoelectric points of the metalloproteinase components were estimated to be 4.9, 4.5 and 4.1 by isoelectric focusing. A fraction with an apparent isoelectric point of 4.9 was the main component. The apparent molecular weight of the main protease component was estimated to be 4.7 × 104 by gel filtration of Sephadex G-100. The enzyme hydrolyzed a natural polypeptide, angiotensin I (Asp-Arg-Val-Tyr-Ile-His-Pro-Phe-His-Leu). Main split sites in the peptide were -Tyr7-Ile5- and -Pro7-Phe8-. The former was the most sensitive site to the soil metalloproteinase concerned.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF00270938
