Institute of Chemical Sciences, Gomal University, Dera Ismail Khan 29050, Pakistan.
Institute of Chemical Sciences, Gomal University, Dera Ismail Khan 29050, Pakistan.
Int J Biol Macromol. 2023 Apr 1;233:123544. doi: 10.1016/j.ijbiomac.2023.123544. Epub 2023 Feb 6.
The present work aims to purify and perform a preliminary analysis on a thermostable serine alkaline protease from a recently identified P. minor. The enzyme was purified 2.7-fold with a 12.4 % recovery using Sephadex G-100 chromatography, DEAE-cellulose, and ammonium sulphate precipitation. The isolated enzyme has a specific activity of 473 U/mg. The purified protease had a molecular mass of 29 kDa, and just one band was seen, which matched the band obtained using SDS-PAGE. High thermostability was demonstrated by the enzymes, which had half-lives of 31.79 and 6.0 min (a 5.3-fold improvement), enthalpies of denaturation (ΔH°) of 119.53 and 119.35 KJ mol, entropies of denaturation (ΔS°) of 32.96 and 41.11 J/mol·K, and free energies of denaturation (ΔG°) of 108.87 and 105.58 KJ mol for the protease enzyme. Studies on the folding and stability of alkaline proteases are important since their use in biotechnology requires that they operate in settings of extreme pH and temperature. According to the kinetic and thermodynamic properties, the protease produced by P. minor is superior to that produced by other sources and previously described plants, and it might find utility in a variety of industrial fields.
本工作旨在从最近鉴定的小孢根霉中纯化和初步分析一种耐热丝氨酸碱性蛋白酶。该酶通过 Sephadex G-100 层析、DEAE-纤维素和硫酸铵沉淀进行纯化,得到 2.7 倍的纯化度和 12.4%的回收率。分离得到的酶具有 473 U/mg 的比活力。纯化的蛋白酶的分子量为 29 kDa,仅出现一条带,与 SDS-PAGE 获得的条带相匹配。该酶具有较高的热稳定性,半衰期分别为 31.79 和 6.0 分钟(提高了 5.3 倍),变性焓(ΔH°)分别为 119.53 和 119.35 KJ/mol,变性熵(ΔS°)分别为 32.96 和 41.11 J/mol·K,以及变性自由能(ΔG°)分别为 108.87 和 105.58 KJ/mol。研究碱性蛋白酶的折叠和稳定性很重要,因为它们在生物技术中的应用需要在极端 pH 和温度条件下进行。根据动力学和热力学性质,小孢根霉产生的蛋白酶优于其他来源和以前描述的植物产生的蛋白酶,并且可能在各种工业领域有应用。