SHORT-TERM ASSAYS OF SOIL PROTEOLYTIC ENZYME ACTIVITIES USING PROTEINS AND DI PEPTIDE DERIVATIVES AS SUBSTRATES
SHORT-TERM ASSAYS OF SOIL PROTEOLYTIC ENZYME ACTIVITIES USING PROTEINS AND DI PEPTIDE DERIVATIVES AS SUBSTRATES
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DOI：
10.1016/0038-0717(72)90038-7
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发表时间：
1972-01-01
影响因子：
9.7
通讯作者：
BUTLER J H A
中科院分区：
文献类型：
--
作者：
LADD J N;BUTLER J H A
描述了在不添加抑菌剂的情况下使用蛋白质和二肽衍生物作为底物快速、精确测定土壤蛋白酶的条件。底物水解速率与土壤浓度成正比；每单位重量土壤中氨基化合物的释放量与培养时间直接相关。研究的土壤在pH、质地、有机质含量和总可交换阳离子方面差异很大，但在pH 8.0和60°C附近表现出最佳蛋白酶活性，并且在优先水解含有疏水性侧链氨基酸的二肽衍生物方面是一致的。然而，土壤对给定二肽衍生物和苯甲酰精氨酸酰胺（BAA）（一种用于“类胰蛋白酶”酶测定的阳离子底物）的相对活性差异很大。苄氧羰基 (Z) 苯丙氨酰亮氨酸在所有调查的土壤中水解得最快。对Z-苯丙氨酰亮氨酸的活性远远超过对蛋白质底物的活性，并且与土壤的粘土含量高度相关，但与有机质含量相关性不太好。
Conditions are described for the rapid and precise assay of soil proteases, using proteins and dipeptide derivatives as substrates in the absence of added bacteriostatic agents. The rate of substrate hydrolysis was proportional to the soil concentration; the release of amino compounds per unit weight of soil was directly related to the incubation time.The soils investigated varied widely in their pH, texture, organic matter content, and total exchangeable cations, but nevertheless exhibited optimal protease activity near pH 8.0 and 60°C, and were consistent in their preferential hydrolysis of dipeptide derivatives containing amino acids with hydrophobic side chains. However, soils varied widely in their relative activities towards a given dipeptide derivative and towards benzoyl arginine amide (BAA), a cationic substrate used in the assay of ‘trypsin-like’ enzymes. Benzyloxycarbonyl (Z) phenylalanyl leucine was hydrolysed most rapidly by all soils investigated. Activities towards Z-phenylalanyl leucine far exceeded those towards protein substrates and were highly correlated with the clay contents of the soils but not well correlated with the organic matter contents.