Key Laboratory of Horticultural Plant Biology, The Ministry of Education, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China.
Key Laboratory of Horticultural Plant Biology, The Ministry of Education, College of Resources and Environment, Huazhong Agricultural University, Wuhan 430070, PR China; Laboratory of Physical Chemistry and Soft Matter, Wageningen University and Research, Stippeneng 4, 6708 WE Wageningen, The Netherlands.
Environ Pollut. 2018 Nov;242(Pt A):298-306. doi: 10.1016/j.envpol.2018.06.096. Epub 2018 Jun 29.
Interaction with natural organic matter (NOM) is hypothesized to impact the fate and bioavailability of enzymes and some hazardous proteins in terrestrial and aquatic environments. By using saturated column transport experiments the transport and deposition of the model enzyme lysozyme (LSZ), in the absence and presence of purified Aldrich humic acid (PAHA), was investigated at a series of mass ratios PAHA/LSZ at pH 5 and 8 and two ionic strength values (0.5 mM and 50 mM KCl solution). PAHA decreased LSZ transport under all conditions. The shapes of breakthrough curves (BTCs) and retention profiles (RPs) during cotransport of both colloids evolved from symmetrical to blocking with time and from flat to hyper-exponential with depth, respectively, in response to increases in mass ratio PAHA/LSZ. The results indicated that the "size-selective retention" and concurrent homo- and hetero-aggregation induced straining, which resulted in preferential retention of relatively large PAHA-LSZ aggregates in the column and elution of relatively small ones. Due to differences in aggregate size, in general, the enzyme activity of LSZ in the effluent was larger and that of the retained LSZ was smaller than that of the influent. Therefore, protein transport process could partially increase the enzyme activity and bring potential environmental hazards.
与天然有机物（NOM）的相互作用被假设会影响酶和一些危险蛋白在陆地和水生环境中的命运和生物利用度。本研究采用饱和柱传输实验，在 pH 值为 5 和 8 以及两种离子强度值（0.5 mM 和 50 mM KCl 溶液）下，研究了在一系列 PAHA/LSZ 质量比下，模型酶溶菌酶（LSZ）在不存在和存在纯化的 Aldrich 腐殖酸（PAHA）时的传输和沉积情况。PAHA 在所有条件下都降低了 LSZ 的传输。胶体共运移过程中，BTC 和 RP 的形状分别从对称到阻塞以及从平坦到超指数随时间和深度而变化，这是由于 PAHA/LSZ 质量比的增加所致。结果表明，“尺寸选择性保留”和同时发生的同聚和异聚诱导的应变导致相对较大的 PAHA-LSZ 聚集体在柱中优先保留，而相对较小的聚集体则被洗脱。由于聚集尺寸的差异，通常，LSZ 的酶活性在流出物中较大，而被保留的 LSZ 的酶活性较小，比流入物中的酶活性小。因此，蛋白质传输过程可能会部分增加酶活性，并带来潜在的环境危害。
