Synthesis and Applications of Site- Specific Analogue of Farnesyltransferase in Reversible Immobilization

Abstract

Protein farnesylation is a post translational modification of proteins catalyzed by protein farnesyltransferases (pFTase), and involves attachment of a farnesyl (15 carbons) isoprenoid moiety to a C-terminal residue of protein containing a CAAX-box motif, where C is cysteine, A is an aliphatic amino acid, and X is a specific amino acid that controls the isoprenoid moiety addition1. The high site specificity of pFTase and its moderate tolerance of subtle changes in farnesyl moiety make farnesylation a valuable method of protein immobilization, and a novel tool for analyzing proteinprotein interactions in chemical biology3. During spring of 2011, I worked on synthesis of a novel farnesyl analogue containing a formylbenzoate moiety and characterized its effectiveness with pFTase to be used in further experimentation in protein immobilization by a Ph. D. candidate, Mohammad Rashidian. The novel farnesyl analogue, Geranyl FormylBenzoate Pyrophosphate (GFBPP), was optimized from original multistep synthesis of seven reactions to five reactions with dramatic increase in final product yield from 5.6% to 14%. Enzymatic evaluation of GFBPP with pFTase showed higher affinity of enzyme to GFBPP at the cost of slower reaction rate. GFBPP was later evaluated as an analogue for rapid reversible protein immobilization using pFTase by Mr. Rashidian.