Antifreeze Polypeptides as Biomineralization Models.
Abstract
During the past three years we have focused on three specific aims: (1) understanding the mechanism of ice-binding by antifreeze polypeptides (AFPs), (2) synthesis and characterization of peptides (CBPs) that alter the morphology of a mineral, calcite, and (3) characterizing the interaction between a specific CBP and calcite. In the course of pursuing aim (1), we discovered, in the longhorn sculpin, a new class (type W) of antifreeze protein and have determined completely both its protein and DNA sequences. It contains 108 amino acids and, we believe, based on secondary structure analysis, folds into a 4-helix bundle. We have designed and synthesized an alpha-helical peptide designed 'de novo' to bind to the prism face of calcite. This peptide has a remarkable effect on calcite crystal morphology: at low temperatures, in its helical form, it does appear to bind to a prism face, but when the peptide is unfolded, it causes epitaxial growth off the rhombohedral surfaces of calcite seed crystals, resulting in very unusual morphology. This is perhaps the first example of a rationally designed, morphology controlling mineral binding peptide. We have also synthesized a helical phosphopeptide which appears to bind to the basal face of calcite.
Document Details
- Document Type
- Technical Report
- Publication Date
- Oct 25, 1997
- Accession Number
- ADA332083
Entities
People
- Richard A. Laursen