INTERCHAIN HYDROGEN BONDING INTERACTIONS BETWEEN FILAMENTS OF ACTIN

氢键相互作用对许多生物的功能至关重要， 生物分子 氢原子的振动模式 键落在远红外区（150-250 cm-1）。 肌动蛋白是 肌肉纤维的主要成分。 单个多肽单元是 称为G-肌动蛋白 当G-肌动蛋白聚合形成肌动蛋白丝时 (i.e.肌肉纤维），它被称为F-肌动蛋白。 F-肌动蛋白丝是 形成为两个G肌动蛋白单体扭曲成螺旋， 认为它们是通过氢键网络结合在一起的 交互. 因此，比较的远红外光谱的 G-H与F-actin的比较提供了一种研究氢键的方法 蛋白质的相互作用 我们已经生长了G-和F-肌动蛋白的薄膜， 聚乙烯盘，并测定其远红外光谱。 我们 在G-和F-肌动蛋白中观察到3种模式（532、544和590 cm-1）。 在 此外，我们观察到在181的F-肌动蛋白光谱中的强烈特征， 和254 cm-1，这在单体G-肌动蛋白中是不存在的，并且可能是 可归因于F-肌动蛋白中的氢键相互作用。 我们计划 继续我们对G-和F-肌动蛋白的研究， 不同的条件下，如在D2 O和不同的盐的存在下， 浓度的 D2 O预计将改变 氢键相互作用和各种盐条件提供了 不同水平的G-肌动蛋白聚合成F-肌动蛋白。 在 此外，红外光的偏振性质将使其 研究肌动蛋白丝的方向是可能的。

ydrogen-bonding interactions are crucial to the function of many biological molecules. The vibrational modes associated with hydrogen bonds fall in the far-infrared region (150-250 cm-1). Actin is the primary component of muscle fibers. The single polypeptide unit is known as G-actin. When G-actin polymerizes to form actin filaments (i.e. muscle fibers), it is called F-actin. F-actin filaments are formed as two G actin monomers are twisted into a helix and it is thought that they are held together by a network of hydrogen-bonding interactions. Thus, a comparison of the far infrared spectra of G-Hversus F-actin provides a method for studying hydrogen-bonding interactions in proteins. We have grown films of G- and F-actin on polyethylene disks and determined their far infrared spectra. We observe 3 modes (532, 544, and 590 cm-1) in both G- and F-actin. In addition, we observe intense features in the F-actin spectrum at 181 and 254 cm-1, which are absent in the monomeric G-actin, and may be assignable to hydrogen bonding interactions in the F-actin. We plan to continue our studies on G- and F-actin by growing films under different conditions, such as in the presence of D2O and varying salt concentrations. D2O is expected to shift the frequency of hydrogen-bonding interactions and various salt conditions provide different levels of polymerization of G-actin into F-actin. In addition, the polarized nature of the infrared light will make it possible to study the orientation of the actin filaments.