Department of Biochemistry and Molecular Biophysics , Kansas State University , 141 Chalmers Hall , Manhattan , Kansas 66506 , United States.
Department of Pharmaceutical Chemistry , University of Kansas , 2095 Constant Ave. , Lawrence , Kansas 66047 , United States.
Biomacromolecules. 2018 Jul 9;19(7):2391-2400. doi: 10.1021/acs.biomac.7b01637. Epub 2018 May 9.
The interactions among biomacromolecules within insect cuticle may offer new motifs for biomimetic material design. CPR27 is an abundant protein in the rigid cuticle of the elytron from Tribolium castaneum. CPR27 contains the Rebers-Riddiford (RR) motif, which is hypothesized to bind chitin. In this study, active magnetic microrheology coupled with microscopy and protein particle analysis techniques were used to correlate alterations in the viscosity of chitosan solutions with changes in solution microstructure. Addition of CPR27 to chitosan solutions led to a 3-fold drop in viscosity. This change was accompanied by the presence of micrometer-sized coacervate particles in solution. Coacervate formation had a strong dependence on chitosan concentration. Analysis showed the existence of a critical CPR27 concentration beyond which a significant increase in particle count was observed. These effects were not observed when a non-RR cuticular protein, CP30, was tested, providing evidence of a structure-function relationship related to the RR motif.
昆虫表皮中生物大分子之间的相互作用可能为仿生材料设计提供新的主题。CPR27 是来自赤拟谷盗鞘翅中的刚性表皮中丰富的蛋白质。CPR27 含有 Rebers-Riddiford (RR) 基序，该基序据推测可与几丁质结合。在这项研究中，结合了显微镜和蛋白质颗粒分析技术的主动磁流变学被用于将壳聚糖溶液粘度的变化与溶液微观结构的变化相关联。向壳聚糖溶液中添加 CPR27 会导致粘度降低 3 倍。这种变化伴随着溶液中出现微米级凝聚物颗粒。凝聚物的形成强烈依赖于壳聚糖的浓度。分析表明，存在一个关键的 CPR27 浓度，超过该浓度后，观察到颗粒计数显著增加。当测试非 RR 表皮蛋白 CP30 时，未观察到这些效应，这为 RR 基序相关的结构-功能关系提供了证据。
