Phosphinic Peptide Matrix Metalloproteinase-9 Inhibitors by Solid-Phase Synthesis Using a Building Block Approach
摘要:
The solid-phase synthesis of an array of different pseudopeptides containing a phosphinic glycine-leucine moiety (-G Psi/{P(O)OH-CH2}L-)([1]) is described. The resulting pseudopeptides were shown to act as matrix metalloproteinase-9 (MMP-9) inhibitors. Starting from available materials, the protected amino acid isosters benzyloxy-carbonyl aminomethylphosphinic acid (glycine analogue) and ethyl alpha-isobutylacrylate (leucine analogue) were synthesized and coupled with the bis(trimethylsilyl)phosphonite. Protective group interchange yielded a protected phosphinic dipeptide building block 1 ready for use in solid-phase peptide synthesis, Solid-phase peptide synthesis was performed with 9-fluorenylmethyloxycarbonyl (Fmoc) chemistry on a polyethylene glycol polyamide (PEGA) support and the coupling of 1 (1.5 equiv) was carried out with standard activation. The P-4-P-2 and P-2'-P-4' positions of the pseudopeptides were designed by analogy of the cleavage sequences of different natural extracellular matrix protein substrates with a synthetic peptide substrate of MMP-9. The crude peptides were obtained in high yield and purity as determined by RP-HPLC, and were characterized by electrospray mass spectrometry and amino acid analysis after purification. Enzyme kinetic investigations with MMP-9 of the purified peptide inhibitors showed Ki values in the range from mM to nM.