An efficient synthesis of a 4'-phosphonodifluoromethyl-3'-formyl-phenylalanine containing SRC SH2 ligand.
A CuBr-mediated, regioselective cross-coupling between methyl 2,5-diiodobenzoate (4) and [(diethoxyphosphinyl)difluoromethyl]zinc bromide is reported. Palladium-catalyzed incorporation of an amino acid side chain, followed by subsequent modifications resulted in the rapid construction of 2. Compound 2 was designed to engage Cys188 of the Src SH2 domain, however, this was not observed spectroscopically.
The SH2 domain: versatile signaling module and pharmaceutical target.
The Src homology 2 (SH2) domain is the most prevalent protein binding module that recognizes phosphotyrosine. This approximately 100-amino-acid domain is highly conserved structurally despite being found in a wide variety proteins. Depending on the nature of neighboring protein module(s), such as catalytic domains and other protein binding domains, SH2-containing proteins play many different roles in cellular protein tyrosine kinase (PTK) signaling pathways. Accumulating evidence indicates SH2 domains are highly versatile and exhibit considerable flexibility in how they bind to their ligands. To illustrate this functional versatility, we present three specific examples: the SAP, Cbl and SOCS families of SH2-containing proteins, which play key roles in immune responses, termination of PTK signaling, and cytokine responses. In addition, we highlight current progress in the development of SH2 domain inhibitors designed to antagonize or modulate PTK signaling in human disease. Inhibitors of the Grb2 and Src SH2 domains have been extensively studied, with the aim of targeting the Ras pathway and osteoclastic bone resorption, respectively. Despite formidable difficulties in drug design due to the lability and poor cell permeability of negatively charged phosphorylated SH2 ligands, a variety of structure-based strategies have been used to reduce the size, charge and peptide character of such ligands, leading to the development of high-affinity lead compounds with potent cellular activities. These studies have also led to new insights into molecular recognition by the SH2 domain.
Monofluorophosphonates as phosphate mimics in bioorganic chemistry: a comparative study of CH2-, CHF- and CF2-phosphonate analogues of sn-glycerol-3-phosphate as substrates for sn-glycerol-3-phosphate dehydrogenase
The synthesis of the cyclohexylammonium salts of 3-(S),4-dihydroxy-1(R,S)-fluorobutylphosphonic acid 3 and 1,1-difluoro-3-(S),4-dihydroxybutylphosphonic acid 4 is reported; 3 is a better substrate for NADH linked sn-glycerol-3-phosphate dehydrogenase than the difluoromethylenephosphonate 4; a comparative study of the CH2-, CHF and CF2- phosphonate analogues of sn-glycerol-3-phosphate is reported.