Asymmetric phase-transfer catalysis was unable to provide the (S)-alpha-Me-o-cyanophenylalanine precursor for (S)-alpha-MeAba in acceptable enantiomeric purity. However, by using a Schollkopf chiral auxiliary, this intermediate was obtained in 88% ee. [(S)-Aba 3-Gly 4] dermorphin retained mu-opioid affinity but displayed an increased delta-affinity. The corresponding R epimer was considerably less potent. In contrast, the [(R)-alpha-MeAba3-Gly4] dermorphin isomer was more potent than its S epimer. Tar-MD simulations of both non-methylated [Aba 3-Gly 4] dermorphin analogues showed a degree of folding at the C-terminal residues toward the N
terminus of the peptide, without SNS-032 purchase however, adopting a stabilized beta-turn conformation. The alpha-methylated analogues, on the other hand, exhibited a type I/I’ beta-turn BI-2536 conformation over the alpha-MeAba3 and Gly4 residues, which was stabilized by a hydrogen bond involving Tyr5-H(N) and D-Ala 2-CO.”
“Achieving effective controllable
delivery of therapeutic biomacromolecules for long action without new molecular entities generation or carriers employed offers a promising alternative and significant clinical benefit. We show here that recombinant human interferon-alpha (rhIFN) can form a three dimensional ordered structure that is featured by spherical semi-crystalline through molecular self-assembly directed by a polycationic short peptide. The phase diagrams for self-assembly were constructed to identify the optimal regions for nucleation and ordered growth, and which were followed by the physico-chemical characterization of the ordered self-assemblies, including morphology, particle size, X-ray diffraction, circular dichroism and biological potency evaluations. With varied molar ratio of the two composed selleckchem biomacromolecules,
the dissolution behaviors of the self-assemblies could be manipulated in vitro and in vivo. The plasma pharmacokinetics suggested that s.c. administration of self-assemblies at the specified relative proportion of rhIFN to polycationic peptide offered a significant prolonged duration time of rhIFN blood levels up to seven days. Moreover, molecular simulation was performed to better understand their binding site and mode. The work described here demonstrates the possibility of spherical ordered self-assembly of biomacromolecules for controllable delivery application of therapeutic proteins. (C) 2012 Elsevier Ltd. All rights reserved.”
“Histone deacetylases (HDACs) counterbalance acetylation of lysine residues, a protein modification involved in numerous biological processes. Here, Hdac1 and Hdac2 conditional knock-out alleles were used to study the function of class I Hdac1 and Hdac2 in cell cycle progression and haematopoietic differentiation.