Spagnoli Chiara, Korniakov Alexander, Ulman Abraham, Balazs Endre A, Lyubchenko Yuri L, Cowman Mary K
Othmer Department of Chemical and Biological Sciences and Engineering, Polytechnic University, 6 Metrotech Center, Brooklyn, NY 11201, USA.
Carbohydr Res. 2005 Apr 11;340(5):929-41. doi: 10.1016/j.carres.2005.01.024.
Extended, relaxed, condensed, and interacting forms of the polysaccharide hyaluronan have been observed by atomic force microscopy (AFM). The types of images obtained depend on the properties of the surfaces used. We have investigated several different surface conditions for HA imaging, including unmodified mica, mica chemically modified with two different kinds of amino-terminated silanes (3-aminopropyltriethoxysilane and N-trimethoxysilylpropyl-N,N,N-trimethylammonium chloride), and highly oriented pyrolytic graphite. We found the degree of HA molecular extension or condensation to be variable, and the number of bound chains per unit area was low, for all of the mica-based surfaces. HA was more easily imaged on graphite, a hydrophobic surface. Chains were frequently observed in high degrees of extension, maintained by favorable interaction with the surface after molecular combing. This observation suggests that the HA macromolecule interacts with graphite through hydrophobic patches along its surface. AFM studies of HA behavior on differing surfaces under well-controlled environmental conditions provides useful insight into the variety of conformations and interactions likely to be found under differing physiological conditions.
通过原子力显微镜（AFM）观察到了多糖透明质酸的伸展、松弛、凝聚和相互作用形式。所获得的图像类型取决于所用表面的性质。我们研究了几种用于透明质酸成像的不同表面条件，包括未改性云母、用两种不同的氨基封端硅烷（3-氨丙基三乙氧基硅烷和N-三甲氧基硅基丙基-N,N,N-三甲基氯化铵）进行化学改性的云母，以及高度取向的热解石墨。我们发现，对于所有基于云母的表面，透明质酸分子的伸展或凝聚程度是可变的，且单位面积内结合链的数量较少。透明质酸在疏水性表面石墨上更容易成像。分子梳理后，通过与表面的有利相互作用，经常观察到高度伸展的链。这一观察结果表明，透明质酸大分子通过其表面的疏水区域与石墨相互作用。在良好控制的环境条件下对透明质酸在不同表面上行为的AFM研究，为深入了解在不同生理条件下可能发现的各种构象和相互作用提供了有用的见解。
