Racemic Hydrogels from Self-Assembling Mirror Image Peptides: Predictions from Pauling and Corey: Nano Seminar Series

Seminar | November 3 | 2-3 p.m. | 180 Tan Hall | Note change in location

 Joel P. Schneider, Deputy Director, NIH Center for Cancer Research

 Berkeley Nanosciences and Nanoengineering Institute

Hydrogels prepared from self-assembling peptides are promising materials for medical applications, and using both L- and D-peptide isomers in a gel’s formulation provides an intuitive way to control the proteolytic degradation of an implanted material. In the course of developing gels for delivery applications, we discovered that a racemic mixture of the mirror-image β-hairpin peptides, named MAX1 and DMAX1, provides a fibrillar hydrogel that is four-times more rigid than gels formed by either peptide alone - a puzzling observation.

Transmission electron microscopy (TEM), small angle neutron scattering (SANS), solid state NMR, diffusing wave, infra-red, and fluorescence spectroscopies, and modeling was used to determine that enantiomeric peptides assembled into a structure predicted by Pauling and Corey in 1953, which provides the molecular basis for the increased mechanical rigidity of the racemic gel.

Molecular level understanding of the gel network allows the rational design of materials for specific applications, for example, multiphase transitioning gels that facilitate the suturing of ultrasmall blood vessels.

Dr. Schneider did his Ph.D. in O-Chem at Texas A&M and postdoc at Penn, Biochemistry and Biophysics. In 1999, he started at the Univ of Delaware, rising to full professor in 2009 with a secondary appointment in MSE. He joined the NCI in 2010 as lab Chief of the newly established Chemical Biology Laboratory and was later appointed Deputy Director in 2015. He currently serves as Executive Editor of Biopolymers-Peptide Science, the journal of the American Peptide Society.