Krishna Ohm D, Kiick Kristi L
Department of Materials Science and Engineering, University of Delaware, Newark, Delaware 19716, USA.
Biomacromolecules. 2009 Sep 14;10(9):2626-31. doi: 10.1021/bm900551c.
The mechanical and biological functions of the native collagens remain an inspiration in materials design, but widespread application of de novo collagens has been limited in part by the need for hydroxylated proline in the formation of stable triple helical structures. To address this continued need and to expand the potential for recombinant expression of functional, hydroxyproline-lacking collagen-mimetic peptides, we have designed a hydrophilic, nonrepetitive, and thermally stable collagen-mimetic peptide via the incorporation of triple-helix-stabilizing charged triplets. The peptide sequence is also equipped with a type III-collagen-mimetic cystine knot at the C-terminus to facilitate covalent cross-linking of the triple helix via simple air oxidation. Circular dichroic spectroscopy (CD) studies of this collagen-mimetic peptide revealed a typical, thermally stable, collagen triple helix signature with a weak positive maximum at 225 nm and a triple helix melting temperature (T(m)) of 35 and 43 degrees C for the reduced and oxidized forms, respectively. The thermal behavior was confirmed via analysis by differential scanning calorimetry. Interestingly, this hydroxyproline-lacking, collagen-mimetic peptide also assembles into nanorods and microfibrillar structures as observed via transmission electron microscopy. The identification and demonstrated useful collagen-mimetic properties of this peptide suggests important opportunities in the recombinant design of new collagen-based biomaterials.
天然胶原蛋白的机械和生物学功能仍然是材料设计的灵感来源，但从头合成胶原蛋白的广泛应用在一定程度上受到限制，因为在形成稳定的三螺旋结构时需要羟基化脯氨酸。为了满足这一持续的需求，并扩大缺乏羟脯氨酸的功能性胶原蛋白模拟肽的重组表达潜力，我们通过引入三螺旋稳定带电三联体，设计了一种亲水性、非重复性且热稳定的胶原蛋白模拟肽。该肽序列在C端还配备了一个III型胶原蛋白模拟胱氨酸结，以通过简单的空气氧化促进三螺旋的共价交联。对这种胶原蛋白模拟肽的圆二色光谱（CD）研究揭示了一种典型的、热稳定的胶原蛋白三螺旋特征，在225 nm处有一个弱的正最大值，还原形式和氧化形式的三螺旋解链温度（T(m)）分别为35和43摄氏度。通过差示扫描量热法分析证实了其热行为。有趣的是，通过透射电子显微镜观察发现，这种缺乏羟脯氨酸的胶原蛋白模拟肽还能组装成纳米棒和微纤维结构。该肽的鉴定及其展示的有用的胶原蛋白模拟特性表明，在新型基于胶原蛋白的生物材料的重组设计中存在重要机遇。
