Synthesis and characterization of a fragment of an ice nucleation protein

Autor: Paul Ala, Daniel S.C. Yang, Vettai S. Ananthanarayanan, Neville Chan, Pele Chong
Rok vydání: 1993
Předmět:
Zdroj: Biochemistry and Cell Biology. 71:236-240
ISSN: 1208-6002
0829-8211
DOI: 10.1139/o93-036
Popis: Synthetic peptides were used as models for studying the conformation of ice nucleation proteins. We chemically synthesized four peptides (16-, 24-, 32-, and 48-mer) that consisted of two to six repeats of the consensus repeating octapeptide unit of ice nucleation proteins and evaluated their conformation by circular dichroism spectroscopy. These model peptides exist predominantly as random coils in aqueous solution, but adopt α-helical structures in the presence of trifluoroethanol. The stability of their secondary structures was investigated by monitoring the pH and time dependence of their circular dichroism spectra. Our results indicated that the α-helical content of the 48-mer exhibited a significant pH dependence, while that of the 24- and 32-mer peptides did not. The 32-mer was the only peptide that transformed from the α-helical to a β-sheet structure upon storage. We suggest that the overall conformation of the ice nucleation protein could be a β-sheet.Key words: ice nucleation protein, synthetic peptides, circular dichroism.
Databáze: OpenAIRE