Exploring the molecular adhesion of ocular mucins
Exploring the molecular adhesion of ocular mucins
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DOI：
10.1021/bm000145y
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发表时间：
2001-06-01
影响因子：
6.2
通讯作者：
Miles, MJ
中科院分区：
文献类型：
--
作者：
Berry, M;McMaster, TJ;Miles, MJ
粘蛋白被认为具有亲粘和抗粘两种功能。为了阐明这两种功能如何体现在同一个分子中，我们研究了人眼粘蛋白与云母和沉积在云母上的粘蛋白的相互作用。粘附能和相互作用力作为接近速度的函数进行评估，最大延伸停留时间，以及成像缓冲液中二价阳离子的存在。粘蛋白被拴在AFM镀金尖端上。对云母的入路和回路进行反复循环，每次循环均发现大量粘连。随着Ni（II）离子的加入和停留时间的延长，附着能（0.2 ~ 48 aJ）和剥离力（0.1 ~ 4 nN）增加。接近的速度对交互作用几乎没有影响。大多数分离发生在距离表面不到40纳米的地方。拆离间距离反映了云母基面上的主要周期性。相互作用的短距离、分离力的大小和粘蛋白在SAM上的成像都表明AFM尖端有可变形的致密粘蛋白聚集体。相互分离的距离表明相邻分子之间有很大程度的相互渗透。粘蛋白与沉积在云母上的粘蛋白不粘附。这种现象与眨眼时眼睑和角膜黏液凝胶的不粘附类似。
Mucins have been ascribed both pro- and anti-adhesive functions. To clarify how both functions can be embodied in the same molecule we studied the interaction of human ocular mucins with mica and with mucins deposited on mica. Adhesion energy and forces of interaction were evaluated as a function of speed of approach, dwell time at maximum extension, and presence of divalent cations in the imaging buffer. Mucins were tethered to an AFM gold-coated tip. Repeated cycles of approach and retract to mica revealed a large number of adhesions in each cycle. Adhesion energy (0.2-48 aJ) and detachment forces (0.1-4 nN) increased with the addition of Ni(II) ions, and with lengthening dwell time. Speed of approach made little difference to the interactions. Most detachments occurred less than 40 nm from the surface. Inter-detachment distances reflected the major periodicities of the mica basal plane. Short distances of interaction, magnitude of detachment forces, and imaging of mucins on SAM all suggest deformable compact mucin aggregates on the AFM tip. Inter-detachment distances suggest a large degree of interpenetration between neighboring molecules. Tip-tethered mucins did not adhere to mucins deposited on mica. This phenomenon is analogous with the nonadherence of the mucin gels on lids and on cornea during blinking.