Department of Biochemistry, University of Missouri, Columbia, 65211, USA.
Anal Biochem. 2011 Jan 1;408(1):172-4. doi: 10.1016/j.ab.2010.09.001. Epub 2010 Sep 7.
Elastolysis is central to progression of emphysema and aortic aneurysms. Characterization of steady-state enzyme kinetics of elastolysis is fettered by the insolubility of mature elastin and the polydispersity of solubilized elastin. We prepared a fluor-tagged, 100-kDa fraction (fEln-100) from commercial α-elastin. It is soluble, less heterogeneous in mass, cross-linked like mature elastin, and likely to retain the capacity of α-elastin to self-assemble. fEln-100 has introduced the ability to compare quantitatively the apparent k(cat) and K(m) of elastases. For example, metalloelastase (MMP-12) displays higher apparent affinity for fEln-100, while MMP-2 displays faster catalytic turnover.
弹性蛋白酶解在肺气肿和主动脉瘤的进展中起着核心作用。由于成熟弹性蛋白的不溶性和可溶性弹性蛋白的多分散性，弹性蛋白酶解的稳态酶动力学特征受到限制。我们从商业α-弹性蛋白中制备了一种荧光标记的 100 kDa 片段（fEln-100）。它是可溶的，质量上的异质性更小，交联方式与成熟弹性蛋白相似，并且可能保留α-弹性蛋白自我组装的能力。fEln-100 引入了定量比较弹性蛋白酶的表观 k(cat) 和 K(m) 的能力。例如，金属弹性蛋白酶（MMP-12）对 fEln-100 表现出更高的表观亲和力，而 MMP-2 显示出更快的催化周转率。
