入藏号：WOS:000515928600013

中国科学院文献情报中心期刊分区： 农林科学1区/TOP（2020年升级版）

本校作者：王吉鹏；黄舜禹

来源出版物： BIOLOGY AND FERTILITY OF SOILS  卷: 56  期: 2  页: 281-285

出版年：2020

第一地址：成都理工大学

关键词：7-Amino-4-methyl-coumarin;L-Leucine-7-amido-4-methylcoumarin;Leucine aminopeptidase;Enzyme assay;protocols ; Alkalization procedure ;Soil enzyme;Introduction

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摘要：The fluorescence responses of 7-amino-4-methylcoumarin (AMC) and L-leucine-7-amido-4-methylcoumarin (L-leucine-AMC)(the fluorescent dye and substrate used in the soil leucine aminopeptidase assay, respectively) to alkalization by NaOH Andtris hydroxymethyl) minomethane (THAM) buffer were analyzed. The leucine aminopeptidase activities were also measuredwithout and with the alkalization procedure using five soils with contrasting properties. The pH optimum of leucine aminopeptidaseactivity was 8 ± 1 for the five studied soils. In this pH range, the alkalization procedure cannot increase the fluorescence ofAMC to improve the assay sensitivity. Excess alkalization (final medium pH of 12 or higher) led to decreasing fluorescence ofAMC with time and non-enzymatic hydrolysis of L-leucine-AMC, which caused irreproducible values of the calculated enzymeactivities. Moreover, a medium pH of ~ 11 cannot terminate the enzymatic reaction, and thus it seems impractical to stop theenzyme reaction by alkalization without causing the unstable behavior ofAMC and L-leucine-AMC.We recommend performingthe soil leucine aminopeptidase assay at the optimal pH without alkalization and reading the fluorescence immediately afterincubation. This approach may help to simplify and standardize the leucine aminopeptidase assay.

文章链接地址: https://link.springer.com/article/10.1007/s00374-019-01419-x