生物谷报道：四川大学研究人员近日在《公共科学图书馆·综合》（PLoS ONE）发表研究论文。
文章首次确认可以使用D型氨基酸构建新型自组装短肽系统，由于D型短肽在体内有更长久的耐受性，因此，这类新型自组装短肽将广泛应用于生物工程如细胞的三维培养、纳米生物医学工程如快速止血、修复神经组织，药物工程如药物控释、蛋白质工程膜蛋白的稳定与结晶等领域。该论文的长远意义是对自组装短肽的研究体系的完善和丰富，对于开启设计符合战略利益的新型纳米生物材料，占领基础科学研究的科技前沿，具有重要的理论价值和实践意义。该文的潜在应用是为自然灾害(地震灾害)和非自然灾害(战争)中的创伤快速修复等带来曙光。（生物谷www.bioon.com）
生物谷推荐原始出处：
PLoS ONE，doi:10.1371/journal.pone.0002364，Zhongli Luo，Shuguang Zhang
Structural Dynamic of a Self-Assembling Peptide d-EAK16 Made of Only D-Amino Acids
Zhongli Luo, Xiaojun Zhao, Shuguang Zhang*
West China Hospital, Laboratory for Nanobiomedical Technology, Sichuan University, Chengdu, Sichuan, China
Abstract
We here report systematic study of structural dynamics of a 16-residue self-assembling peptide d-EAK16 made of only D-amino acids. We compare these results with its chiral counterpart L-form, l-EAK16. Circular dichroism was used to follow the structural dynamics under various temperature and pH conditions. At 25°C the d-EAK16 peptide displayed a typical beta-sheet spectrum. Upon increasing the temperature above 70°C, there was a spectrum shift as the 218 nm valley widens toward 210 nm. Above 80°C, the d-EAK16 peptide transformed into a typical alpha-helix CD spectrum without going through a detectable random-coil intermediate. When increasing the temperature from 4°C to 110°C then cooling back from 110°C to 4°C, there was a hysteresis: the secondary structure from beta-sheet to alpha-helix and then from alpha-helix to beta-sheet occurred. d-EAK16 formed an alpha-helical conformation at pH0.76 and pH12 but formed a beta-sheet at neutral pH. The effects of various pH conditions, ionic strength and denaturing agents were also noted. Since D-form peptides are resistant to natural enzyme degradation, such drastic structural changes may be exploited for fabricating molecular sensors to detect minute environmental changes. This provides insight into the behaviors of self-assembling peptides made of D-amino acids and points the way to designing new peptide materials for biomedical engineering and nanobiotechnology.
