Laboratory of Analytical Chemistry, Department of Chemistry, University of Helsinki, P. O. Box 55, 00014 Helsinki, Finland.
Anal Bioanal Chem. 2010 Feb;396(4):1373-80. doi: 10.1007/s00216-009-3371-y. Epub 2009 Dec 30.
Atherosclerosis has received wide attention as a primary cause of premature death in developed countries. The retention of low-density lipoprotein (LDL) particles in the intima, the inner layer of the capillaries, has been imputed as the main cause of the development of atherosclerotic plaques. The entrapment of LDL is mainly due to the specific interaction between the lysine-rich site on apolipoprotein B-100 (apoB-100), a major apolipoprotein of LDL, and extracellular matrix (ECM) components such as collagen, proteoglycans, and glycosaminoglycans (GAGs). Although valuable techniques already exist for studies on apoB-100 and ECM interactions, there is continued need for miniaturized tools that can complement the tools already available and even provide totally new data. This work explores the applicability of the quartz crystal microbalance (QCM) for interaction studies between apoB-100 peptide fragments and various components of the ECM. Two positive peptide fragments, PP and PP(2), and two components of the ECM, collagen I and a selected GAG, chondroitin 6-sulfate (C6S), were immobilized on polystyrene and carboxyl sensor chips. C6S was injected as analyte for PP- and PP(2)-coated surfaces, while PP was the analyte for collagen I and C(6)S surfaces. The estimated dissociation constant (K(D)) indicates that the interactions occur via the positive residues, lysine and arginine, of apoB-100. The continuous-flow QCM system employed in this study is shown to be an excellent tool for the elucidation of interactions between these types of biomolecules.
动脉粥样硬化作为发达国家早逝的主要原因受到广泛关注。富含赖氨酸的载脂蛋白 B-100（apoB-100）的赖氨酸残基与细胞外基质（ECM）成分如胶原、蛋白聚糖和糖胺聚糖（GAGs）之间的特异性相互作用，导致 LDL 颗粒在内皮（毛细血管的内层）中滞留，被认为是动脉粥样硬化斑块发展的主要原因。尽管已经存在有价值的技术来研究 apoB-100 和 ECM 相互作用，但仍然需要小型化的工具来补充现有的工具，甚至提供全新的数据。这项工作探讨了石英晶体微天平（QCM）在 apoB-100 肽片段与 ECM 各种成分之间相互作用研究中的适用性。两种阳性肽片段 PP 和 PP(2)，以及 ECM 的两种成分，I 型胶原和选定的 GAG，硫酸软骨素 6-硫酸盐（C6S），被固定在聚苯乙烯和羧基传感器芯片上。C6S 作为分析物被注入到 PP-和 PP(2)-涂层表面，而 PP 则是胶原 I 和 C(6)S 表面的分析物。估计的解离常数（K(D)）表明，相互作用通过 apoB-100 的阳性残基赖氨酸和精氨酸发生。本研究中使用的连续流动 QCM 系统被证明是阐明这些类型生物分子之间相互作用的优秀工具。
