It is the ultimate aim of this study to gain a better understanding of what constitutes the active site of insulin. In this study we will be using the methods of peptide chemistry; i.e. semisynthesis and total synthesis in respect of the synthesis of each individual disulfide link. Our approach differs significantly from the previous attempted identification of active site residues in that we are trying to test whole areas of the insulin molecule and transplant those into a carrier of identical structure but different amino acid sequence. Such a carrier has fortuitously became available with the discovery that the hormone relaxin has a structure identical to that of insulin, but different amino acid sequence and no biological or immunological crossreactivity with insulin. Physical chemical and biological properties of the resulting hybrids will be determined. Should these study be successful a long-term object might be the design and synthesis of minimum insulin consisting of the active site and kept in the proper position by a minimum frame. Such a molecule might be relatively stable to influences such as acid, peptic and tryptic digests, and stable to the attack by exopeptidases. Furthermore, we hope that such a molecule might be designed to be absorbed readily through the gut and thus ultimatively provide a relief from daily injections for insulin- dependent diabetics.

Agency
National Institute of Health (NIH)
Institute
National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK)
Type
First Independent Research Support & Transition (FIRST) Awards (R29)
Project #
1R29DK038348-01A1
Application #
3462536
Study Section
Physiological Chemistry Study Section (PC)
Project Start
1988-03-01
Project End
1993-02-28
Budget Start
1988-03-01
Budget End
1989-02-28
Support Year
1
Fiscal Year
1988
Total Cost
Indirect Cost
Name
Medical University of South Carolina
Department
Type
Schools of Medicine
DUNS #
183710748
City
Charleston
State
SC
Country
United States
Zip Code
29425
Bullesbach, E E; Schwabe, C (1995) Structural contribution of the A-chain loop in relaxin. Int J Pept Protein Res 46:238-43
Bullesbach, E E; Schwabe, C (1994) Functional importance of the A chain loop in relaxin and insulin. J Biol Chem 269:13124-8
Bullesbach, E E; Schwabe, C (1993) Mouse relaxin: synthesis and biological activity of the first relaxin with an unusual crosslinking pattern. Biochem Biophys Res Commun 196:311-9
Bullesbach, E E; Yang, S; Schwabe, C (1992) The receptor-binding site of human relaxin II. A dual prong-binding mechanism. J Biol Chem 267:22957-60
Yang, S; Rembiesa, B; Bullesbach, E E et al. (1992) Relaxin receptors in mice: demonstration of ligand binding in symphyseal tissues and uterine membrane fragments. Endocrinology 130:179-85
Bullesbach, E E; Schwabe, C (1991) Total synthesis of human relaxin and human relaxin derivatives by solid-phase peptide synthesis and site-directed chain combination. J Biol Chem 266:10754-61
Schwabe, C; Bullesbach, E E (1990) Relaxin. Comp Biochem Physiol B 96:15-21
Bullesbach, E E; Schwabe, C (1990) Monobiotinylated relaxins. Preparation and chemical properties of the mono(biotinyl-epsilon-aminohexanoyl) porcine relaxin. Int J Pept Protein Res 35:416-23