110392-41-1Relevant academic research and scientific papers
Solid-phase synthesis of arginine-containing peptides and fluorogenic substrates using a side-chain anchoring approach
Hamze, Abdallah,Martinez, Jean,Hernandez, Jean-Francois
, p. 8394 - 8402 (2007/10/03)
Attachment of an amino acid to a solid support by its side chain is sometimes necessary to take advantage of an α-carboxylic group available for diverse modifications, including the incorporation of a fluorophore for the preparation of fluorogenic substrates. In contrast to most other amino acids, anchoring the guanidinium group of an arginine to a resin requires the use of a supplementary linker. To avoid the usually multistep synthesis of such a linker as well as its difficult attachment to the guanidine group, we developed a simple method where the guanidine group is built on a Rink amide resin. Our strategy followed the steps of guanidine formation: (i) addition of an isothiocyanate derivative of ornithine to the amino group of a solid support, yielding Nω-linked thiocitrulline; (ii) S-methylation of thiourea; (iii) guanidinylation using ammonium acetate. Cleavage of the resin generated the arginine-containing compound, the amine group of the resin becoming part of the guanidine. We have demonstrated the usefulness of this method by the synthesis of a series of fluorogenic substrates for trypsin-like serine proteases, which were obtained in high yield and purity. Then, our strategy also allowed generation from the same precursor differentially substituted arginine derivatives, including Nω-methyl- and Nω-ethylarginines. The ability to prepare such analogues together with the intermediates thiocitrulline and S-methylisothiocitrulline from a unique precursor while the α-amine and carboxylic groups remain available for modification also makes this method a powerful tool for combinatorial solid-phase synthesis of NO synthase inhibitors.
Mapping the binding site of tissue kallikrein: Preparation and testing of all possible substrate analog inhibitors homologous with the sequence of kininogen between Ser386 and Gln392
Deshpande,Burton
, p. 3094 - 3102 (2007/10/02)
Programs aimed at converting peptide inhibitors of proteolytic enzymes into more traditional drug structures require an understanding of the role played by the individual amino acid residues in the inhibitor. To this end, all possible substrate analogues occurring within the sequence Ser386-Pro- Phe-Arg-Ser-Val-Gln392 from bovine kininogen were synthesized and tested as inhibitors of tissue kallikrein (EC 3.4.21.35, β-PPK). Of the 21 sequences which can be formed from the heptapeptide, 11 have inhibitory constants which could be measured in the chromogenic assay employed in these studies. No dipeptide and only one tripeptide, Ac-Phe-Arg-Ser-NH2 (K(i) = 718 μM), measurably inhibits the enzyme. All longer peptides inhibit β-PPK. The heptapeptide Ac-Ser-Pro-Phe-Arg-Ser-Val-Gln-NH2 is the most effective inhibitor in this series (K(i) = 101 μM). Each amino acid residue in the sequence appears to alter binding in a relatively independent manner. The N- terminal seryl residue (P4) and the prolyl residue (P3) slightly improve the K(i) of the various inhibitors. The phenylalanyl residue at P2 appears to have a more pronounced effect on K(i). The arginyl residue at P1 and the seryl residue at P1' appear to be the most important residues in the inhibitory sequence. They contribute approximately one-third and one-fourth of the binding energy to the interaction between the substrate analogues and β-PPK, respectively. The valyl residue at P2', and the C-terminal glutaminyl residue improve K(i) of each of the peptides tested. Almost 80% of the binding energy of the substrate analogue inhibitors comes from the core sequence Phe-Arg-Ser which occurs between P2 and P1'. Molecular models developed from the Chen-Bode coordinates of the aprotinin-β-PPK complex have been used to interpret the results of these studies.
α-Melanotropin: The Minimal Active Sequence in the Frog Skin Bioassay
Hruby, Victor J.,Wilkes, Brian C.,Hadley, Mac E.,Al-Obeidi, Fahad,Sawyer, Tomi K.,et al.
, p. 2126 - 2130 (2007/10/02)
The minimal sequence required for biological activity of α-MSH (α-melanotropin, α-melanocyte stimulating hormone) was determined in the frog (Rana pipiens) skin bioassay.The sequence required to elicit measurable biological activity was the central tetrap
