Synthesis and properties of disulfide-bond containing eight-membered rings

ORGN 440

Erik L. Ruggles, Erik.Ruggles@uvm.edu1, Robert J. Hondal, Robert.Hondal@uvm.edu1, and P. Bruce Deker, P.Deker@uvm.edu2. (1) Department of Biochemistry, University of Vermont, Given Laboratory, 89 Beaumont Ave, Burlington, VT 05405, (2) Department of Chemistry, University of Vermont, Cook Physical Sciences Building, 82 University Place, Burlington, VT 05405
Disulfide bonds between adjacent cysteine residues in a peptide or protein are an extremely rare occurrence due to the formation of a strained eight-membered ring structure. These cyclocystine rings (CCRs) have an important structural or functional role in the few proteins that do posses it. This study focuses on: (i) The construction of CCR mimics, (ii) analysis of CCR conformation, and (iii) determination of the redox potentials of the constructed mimics. The CCR mimics are constructed to constrain the geometry of the eight-membered ring about a central bond into either a cis, trans, or unconstrained geometry. Our results show that the CCR mimic containing a cis alkene has very low redox potential as compared to the trans or unconstrained compounds. The results show that disulfide bonds between adjacent residues in a protein are highly strained and are prone to thiol-disulfide exchange.

 

Bioorganic, Metal-Mediated Reactions, and Molecular Recognition
8:00 PM-10:00 PM, Tuesday, 30 August 2005 Washington DC Convention Center -- Hall A, Poster

Division of Organic Chemistry

The 230th ACS National Meeting, in Washington, DC, Aug 28-Sept 1, 2005