1. The enthalpies of interactions of some L-alpha-amino acids with urea molecule in aqueous solutions at 298.15 K
B Pałecz Amino Acids. 2004 Dec;27(3-4):299-303. doi: 10.1007/s00726-004-0132-2. Epub 2004 Oct 22.
Dissolution enthalpies of L-alpha-aminobutyric acid, L-alpha-isoleucine, L-alpha-phenylalanine, L-alpha-methionine, L-alpha-serine, L-alpha-threonine, L-alpha-cysteine, L-alpha-asparagine and L-alpha-glutamine in aqueous solutions of urea have been measured by calorimetry at 298.15 K. The obtained results were used to calculate the enthalpic interaction coefficients between the zwitterions of the L-alpha-amino acids and a molecule of urea in water. These values were interpreted in terms of the hydrophobic or hydrophilic effects of the side chains of amino acids on their interactions with a polar molecule of urea in water.
2. Peptide-based inhibitors of hepatitis C virus full-length NS3 (protease-helicase/NTPase): model compounds towards small molecule inhibitors
Karin Oscarsson, Anton Poliakov, Stefan Oscarson, U Helena Danielson, Anders Hallberg, Bertil Samuelsson Bioorg Med Chem. 2003 Jul 3;11(13):2955-63. doi: 10.1016/s0968-0896(03)00190-1.
From L-alpha-aminobutyric acid (Abu) a set of electrophilic and non-electrophilic replacements for the P1 cysteine of substrate and product inhibitors of hepatitis C virus full-length NS3 (protease-helicase/NTPase) serine protease have been synthesised and coupled to a model pentapeptide furnishing a set of hexapeptide inhibitors. Promising inhibitory activities with K(i) values of 0.18 microM (11b, P1 electrophilic alpha,beta-unsaturated ketone), 0.46 microM (12e, P1 electrophilic alkyl ketone) and 0.98 microM (10e, P1 non-electrophilic alkenyl alcohol as diastereomeric mixture). The reference hexapeptide product inhibitor had a K(i) value of 1.54 microM (14, P1 Abu-OH). The electrophilic inhibitors exhibit increased potency as compared with the corresponding product inhibitor, and notably also the non-electrophilic P1 alkenyl alcohol 10e. This represents the first example of non-electrophilic inhibitors that are not P1 amides or product inhibitors.
