The effect of hydrophilic adhesive monomers on the stability of type I collagen
The effect of hydrophilic adhesive monomers on the stability of type I collagen
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DOI：
10.1016/j.biomaterials.2004.10.010
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发表时间：
2005-06-01
期刊：
影响因子：
14
通讯作者：
Terada, Y
中科院分区：
文献类型：
--
作者：
Nezu, T;Nishiyama, N;Terada, Y
研究了中性单体甲基丙烯酸2-羟乙基酯（HEMA）和酸性单体n -甲基丙烯酰甘氨酸（NMGly）在酸性pH条件下对I型胶原结构稳定性的吸附效果。差示扫描量热法（DSC）测量来评估变性温度（T-d），这是蛋白质结构稳定性的测量，包括牛腱胶原（BTC）。HEMA使BTC的T-d随HEMA浓度线性降低，而NMGly则呈现两步下降。NMGly对T-d的降低率远远大于HEMA的降低率。在T-d与C-NMGly图中，第一步的斜率大于第二步。通过对不同浓度的单体溶液、浸没BTC前后的红外吸收测量，估计了这两种单体对BTC的吸附程度。HEMA对BTC的吸附和BTC的T-d均与HEMA浓度呈线性关系。相反，NMGly被吸附到BTC上，同样以两步减少的方式，类似于T-d与C-NMGLy的分布。在0.013 mol%以下，NMGly的吸附增强，这可能归因于强静电相互作用。对与BTC相同类型的胶原蛋白的圆二色性测量，在不存在和存在单体的情况下，表明天然胶原蛋白的螺旋结构几乎不受单体的影响。结果表明：(1)这两种单体都吸附在BTC上，从而破坏了三螺旋胶原结构的稳定性；(2)在pH = 3的情况下，NMGly的效果更高，与带相反电荷的胶原之间的静电吸引可能有效。如果与HEMA相比，酸性的NMGly是一种潜在的单体，它与胶原蛋白结合强烈，几乎不被水解。(C) 2004 Elsevier Ltd.版权所有。
The adsorption effects of adhesive monomers on the structural stability of type I collagen were studied at an acid pH condition for two monomers: 2-hydroxyethyl methacrylate (HEMA), a neutral monomer and N-methacryloyl glycine (NMGly), an acidic monomer. Differential scanning calorimetry (DSC) measurements were done to assess the denaturation temperature (T-d), which is a measure of the structural stability of the proteins, including the bovine tendon collagen (BTC). While HEMA lowered the T-d of the BTC linearly with HEMA concentrations, NMGly exhibited a two-step decrease of the T-d. The rate of decrease in the T-d by the NMGly was by far greater than the rate of decrease with the HEMA. The first step had a larger slope than the second step in the T-d vs. C-NMGly plot. The degree of adsorption of these two monomers to the BTC was estimated from infrared absorption measurements on the monomer solutions of various concentrations, before and after the immersion of the BTC. Both the adsorption of HEMA to the BTC and the T-d of the BTC were linearly dependent on HEMA concentrations. Conversely, NMGly was adsorbed to the BTC, again, in a two-step decrease similar to the T-d vs. C-NMGLy profile. An enhanced adsorption of NMGly, which might be attributed to a strong electrostatic interaction, was observed below 0.013 mol%. Circular dichroism measurements of the collagen of the same type as the BTC, in the absence and in the presence of the monomers, revealed that the native collagen helix structure was scarcely affected by the monomers. From these observations, it was concluded that (1) both of the monomers were adsorbed onto the BTC, which thus destabilized the triple helical collagen structure, and that (2) the effect was higher for NMGly in which the electrostatic attraction with the oppositely charged collagen might be effective at a pH of 3. If compared to HEMA, an acidic NMGly is a potential monomer that binds strongly to collagen and one that is hardly hydrolyzed. (C) 2004 Elsevier Ltd. All rights reserved.