MOLECULAR FORCES IN CELLULAR ASSEMBLY

除了通过长程物理力相互作用外，大分子或 膜通常通过碰撞或空间力相互作用， 弯曲或旋转的运动。 在过去的一年里，我们解决了 用公式表示这种运动并估计其结果力的问题 在潜在的远程物理同时作用期间， 力 我们现在正在建立一种新的分子间关联 相互作用和分子构象。 DNA双螺旋之间的力的测量揭示了非常强的 显然由重组水溶剂介导的吸引力 分子之间的相互作用，并通过与分子表面的离子结合来调节。 这种吸引力在许多方面类似于通常的“疏水力”。 被认为发生在非极性表面之间。 在我们看来， 在许多情况下，它被用来解释大分子的性质， 这种力可能是由极性分子产生的 强的，特定的，调节的相互作用，必须解释分子 组装件. 对脂质系统的研究现已扩展到测量 形成水腔的功。 我们正在把这些 能量转移到那些参与膜离子通道形成的能量 运输

Besides interacting by long-range physical forces, large molecules or membranes often interact by bumping or steric forces due to the mechanical motion of bending or rotating. This past year we solved the difficult problem of formulating such motion and estimating its consequent forces during the simultaneous action of the underlying long-range physical force. We now are making a new kind of correlation between molecular interactions and molecular conformation. Measurements on forces between DNA double helices reveal very strong attractive forces apparently mediated by restructuring water solvent between molecules and regulated by ion binding to the molecular surface. This attraction in many ways resembles the "hydrophobic force" usually thought to occur between nonpolar surfaces. It appears to us that in the many cases where it has been invoked to explain macromolecular properties that this force can be due to polar molecules and that it can be the strong, specific, and modulated interaction necessary to explain molecular assembly. Investigations on lipid systems have now been extended to measuring the work of forming aqueous cavities. We are in the process of relating these energies to those involved in the formation of ionic channels in membrane transport.