Effects of enzymes on elastic modulus of low-density lipoproteins were investigated using atomic force microscopy
Effects of enzymes on elastic modulus of low-density lipoproteins were investigated using atomic force microscopy
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DOI：
10.1016/j.bbrc.2018.04.211
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发表时间：
2018-06-27
影响因子：
3.1
通讯作者：
Chiba, Hitoshi
中科院分区：
文献类型：
--
作者：
Takeda, Seiji;Sakurai, Toshihiro;Chiba, Hitoshi
低密度脂蛋白(LDL)的氧化可导致心血管疾病的发生。最近，有关原子力显微镜(AFM)研究的报道表明，金属诱导的氧化LDL的弹性模数低于氧化前的弹性模数。然而，弹性模量的变化机理还没有得到很好的研究。我们推测，低密度脂蛋白结构的紊乱可能会降低弹性模数。本研究测定了V8酶、α-糜蛋白酶和磷脂酶A(2)处理前后低密度脂蛋白的弹性模量。用超速离心法从血清中提取低密度脂蛋白后，对低密度脂蛋白或酶处理的低密度脂蛋白进行物理吸收。他们挤在云母表面。虽然V8蛋白水解酶和α-胰凝乳酶不能引起弹性模量值的变化，但经聚乳酸(2)处理后，弹性模量值降低。在酶处理过程中，低密度脂蛋白的颗粒大小没有变化。结果提示，低密度脂蛋白的脂质结构紊乱可能是导致弹性模数变化的原因之一。结果表明，原子力显微镜可能是一种有用的工具，以评估复杂的纳米级颗粒结构的脂质和蛋白质，如脂蛋白的紊乱。(C)2018 Elsevier Inc.保留所有权利。
Oxidation of low-density lipoproteins (LDLs) induces development of cardiovascular disease. Recently, reports of studies using atomic force microscopy (AFM) have described that the elastic modulus of metal induced oxidized LDLs is lower than the modulus before oxidation. However, the mechanisms of change of the elastic modulus have not been well investigated. We postulated that disorder of the LDL structure might decrease the elastic modulus. This study measured the elastic modulus of LDLs before and after enzyme treatment with V8 protease, alpha-chymotrypsin, and phospholipase A(2). After LDLs were obtained from serum by ultracentrifugation, LDLs or enzyme-treated LDLs were physically absorbed. They were crowded on a mica surface. Although V8 protease and alpha-chymotrypsin did not induce the elastic modulus change, treatment with PLA(2) decreased the elastic modulus. The LDL particle size did not change during the enzyme treatment. Results suggest that disordering of the lipid structure of the LDL might contribute to the elastic modulus change. Results show that AFM might be a useful tool to evaluate disorders of complex nanoscale particle structures from lipids and proteins such as lipoproteins. (C) 2018 Elsevier Inc. All rights reserved.