Biophysical characterization of the amylin-derived peptide pramlintide

BIOT 226

Akihisa Nonoyama, nonoyama@ku.edu1, Jennifer S. Laurence, laurencj@ku.edu2, Liza Garriques3, Hong Qi3, Thao Le3, and C. Russell Middaugh, middaugh@ku.edu1. (1) Department of Pharmaceutical Chemistry, University of Kansas, Lawrence, KS 66047, (2) Depts. of Pharmaceutical Chemistry and Chemical & Petroleum Engineering, The University of Kansas, Multidisciplinary Research Building, 2030 Becker Dr, Lawrence, KS 66047, (3) Amylin Pharmaceuticals, Inc, San Diego, CA 92121
AC137 (pramlintide) is a 37-residue peptide analogue of the hormone amylin. Pramlintide has been studied as an antihyperglycemic adjunct treatment for patients with type-2 or type-1 diabetes who use insulin. This study has taken an empirical phase diagram (EPD) -based approach to obtain structural stability information of this peptide by compiling thermal perturbation data acquired from multiple spectroscopic methods including high-resolution second-derivative UV absorbance spectroscopy, optical density, fluorescence and circular dichroism. The multi-pronged analysis allowed us to obtain information about the peptide's secondary and tertiary structures as well as its aggregation behavior, all as functions of temperature and pH. Although low concentrations of the peptide were shown to be stable across the entire pH range (4-8) examined, high concentrations produced a tendency for pramlintide to aggregate at certain pH values. This comprehensive characterization of the peptide's innate structural properties provides a basis for further work aimed at stabilizing the molecule.
 

Biophysical and Biomolecular Symposium: Protein Aggregation
3:00 PM-5:20 PM, Wednesday, August 22, 2007 BCEC -- 108, Oral

Division of Biochemical Technology

The 234th ACS National Meeting, Boston, MA, August 19-23, 2007