Gaczynska Maria, Osmulski Pawel A
Department of Molecular Medicine, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78245, USA.
Methods Cell Biol. 2008;90:39-60. doi: 10.1016/S0091-679X(08)00803-0.
Proteasome is an exceptional enzyme because of its essential physiological role, multiple activities, and structural complexity. It is, in fact, a family of enzymes sharing a common catalytic core and equipped with distinct protein attachments regulating the core and adding to its new functional capabilities. As a drug target and a major regulator of cellular processes, proteasome is extensively studied with tools of structural, biochemical, and molecular biology. Atomic force microscopy (AFM) besides X-ray crystallography and electron microscopy is one of the most attractive methods to study proteasome. The noninvasive nature of this method is particularly well suited for investigating the structure-function relationship within the core particle (CP) as well as in higher-order assemblies. Here we review, from the methodological point of view, AFM-based studies on the proteasome. First, we will present the application of height distribution analysis of proteasome complexes to dissect the subunit organization in the base of the regulatory particle (RP). The RP is considered the most physiologically important among all the attachments of the CP; however, its structure remains enigmatic. Then, we will outline the use of AFM imaging to research on structural dynamics of the proteasome, a phenomenon which is starting to gain a broad interest. We will finish with a brief presentation of nanotechnological studies performed using ordered proteasomes and nanolithography carried out with the particles. The presented AFM research offers a unique and often unexpected insight into the structure and function of the proteasome.
蛋白酶体是一种特殊的酶，因其具有重要的生理作用、多种活性和结构复杂性。实际上，它是一类酶，共享一个共同的催化核心，并配备有独特的蛋白质附件，这些附件调节核心并赋予其新的功能。作为一种药物靶点和细胞过程的主要调节因子，蛋白酶体通过结构、生化和分子生物学工具进行了广泛研究。除了X射线晶体学和电子显微镜外，原子力显微镜（AFM）是研究蛋白酶体最具吸引力的方法之一。这种方法的非侵入性特别适合于研究核心颗粒（CP）以及高阶组装体中的结构-功能关系。在这里，我们从方法论的角度回顾基于AFM的蛋白酶体研究。首先，我们将介绍蛋白酶体复合物高度分布分析在剖析调节颗粒（RP）基部亚基组织方面的应用。RP被认为是CP所有附件中生理上最重要的；然而，其结构仍然神秘。然后，我们将概述AFM成像在研究蛋白酶体结构动力学方面的应用，这一现象开始引起广泛关注。我们将以使用有序蛋白酶体进行的纳米技术研究和用这些颗粒进行的纳米光刻的简要介绍作为结尾。所展示的AFM研究为蛋白酶体的结构和功能提供了独特且常常意想不到的见解。
