Gelation kinetics of β-hairpin peptide hydrogel networks
Gelation kinetics of β-hairpin peptide hydrogel networks
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DOI：
10.1021/ma0609331
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发表时间：
2006-09-19
期刊：
影响因子：
5.5
通讯作者：
Furst, Eric M.
中科院分区：
文献类型：
--
作者：
Veerman, Cecile;Rajagopal, Karthikan;Furst, Eric M.
用微流变学和远紫外圆二色光谱研究了发夹肽MAX 1自组装水凝胶的成胶动力学。这种肽的分子内折叠被设计成控制其自组装成富含β-片层的水凝胶。当肽未折叠时，它不会自组装，水溶液具有水的粘度。折叠和随后的自组装是由pH值、温度或离子强度的变化触发的。这种折叠和自组装机制允许对材料形成的时间控制。CD光谱显示，β-片结构形成的动力学以浓度依赖的方式发生，但没有提供关于网络组装的动力学的信息。在这里，多粒子跟踪用于定义作为肽浓度的函数的精确凝胶化时间。这允许在流变学定义的凝胶化时间和通过CD测量的β-折叠形成的开始之间建立经验关系。在216 nm处，在-10 × 10（3）和-12 × 10（3）deg dmol（-1）cm（2）之间的平均-残基椭圆率值与澄清凝胶的形成相一致.重要的是，这种经验关系允许人们仅从光谱测量中识别凝胶时间，极大地促进了肽序列材料-功能关系的建立。
The gelation kinetics of self- assembled hydrogels consisting of the,- hairpin peptide MAX1 are investigated using microrheology and far- UV circular dichroism ( CD) spectroscopy. The intramolecular folding of this peptide is engineered to control its self- assembly into,- sheet- rich hydrogels. When the peptide is unfolded, it does not self- assemble, and aqueous solutions have the viscosity of water. Folding and consequent self- assembly are triggered by changes in pH, temperature, or ionic strength. This folding and self- assembly mechanism allows temporal control of the material formation. CD spectroscopy shows that the kinetics of,- sheet structure formation occurs in a concentration- dependent manner but does not provide information on the kinetics of network assembly. Here, multiple particle tracking is used to define exact gelation times as a function of peptide concentration. This allows an empirical relationship to be established between the rheologically defined gelation time and the onset of beta-sheet formation as measured by CD. Values of the mean- residue ellipticity at 216 nm between - 10 x 10(3) and - 12 x 10(3) deg dmol(-1) cm(2) coincide with the formation of a percolating gel. Critically, this empirical relationship allows one to identify the gel time solely from spectroscopic measurements, greatly facilitating the establishment of peptide sequence material- function relationships.