Evaluation of Synthetic FK506 Analogues as Ligands for the FK506-Binding Proteins 51 and 52
摘要:
The FK506-binding proteins (FKBP) 51 and 52 are cochaperones that modulate the signal transduction of steroid hormone receptors. Both proteins have been implicated in prostate cancer. Furthermore, single nucleotide polymorphisms in the gene encoding FKBP51 have been associated with a variety of psychiatric disorders. Rapamycin and FK506 are two macrocyclic natural products that bind to these proteins indiscriminately but with nanomolar affinity. We here report the cocrystal structure of FKBP51 with a simplified alpha-ketoamide analogue derived from FK506 and the first structure-activity relationship analysis for FKBP51 and FKBP52 based on this compound. In particular, the tert-pentyl group of this ligand was systematically replaced by a cyclohexyl ring system, which more closely resembles the pyranose ring in the high-affinity ligands rapamycin and FK506. The interaction with FKBPs was found to be surprisingly tolerant to the stereochemistry of the attached cyclohexyl substituents. The molecular basis for this tolerance was elucidated by X-ray cocrystallography.
Investigating<i>Saccharomyces cerevisiae</i>alkene reductase OYE 3 by substrate profiling, X-ray crystallography and computational methods
作者:Robert W. Powell, III、M. Pilar Buteler、Sunidhi Lenka、Michele Crotti、Sara Santangelo、Matthew J. Burg、Steven Bruner、Elisabetta Brenna、Adrian E. Roitberg、Jon D. Stewart
DOI:10.1039/c8cy00440d
日期:——
X-ray crystalstructures of unliganded and phenol-bound OYE 3 were solved to 1.8 and 1.9 Åresolution, respectively. Both structures were nearly identical to that of OYE 1, with only a single amino acid difference in the active site region (Ser 296 versus Phe 296, part of loop 6). Despite their essentially identical static X-ray structures, molecular dynamics (MD) simulations revealed that loop 6 conformations
Catalytic asymmetric hydroxymethylation of silicon enolates has been achieved. In this reaction, an aqueous solution of formaldehyde can be used to realize an easy and safe procedure, and high enantioselectivities have been obtained. This is the first example of catalytic asymmetric reactions in aqueous media with a chiral scandium complex.
Structural and Catalytic Characterization of Pichia stipitis OYE 2.6, a Useful Biocatalyst for Asymmetric Alkene Reductions
作者:Yuri A. Pompeu、Bradford Sullivan、Adam Z. Walton、Jon D. Stewart
DOI:10.1002/adsc.201200213
日期:2012.7.9
We have probed Pichiastipitis CBS 6054 Old Yellow Enzyme 2.6 (OYE2.6) by several strategies including X‐ray crystallography, ligand binding and catalytic assays using the wild‐type as well as libraries of site‐saturation mutants. The alkene reductase crystallized in space group P 63 2 2 with unit cell dimensions of 127.1×123.4 Å and its structure was solved to 1.5 Å resolution by molecular replacement
water-compatible amino-acid-based catalysts was explored in the development of diastereo- and enantioselectivedirectaldolreactions of a broad range of substrates. Chiral C2-symmetrical proline- and valine-based amides and their ZnII complexes were designed for use as efficient and flexible chiral catalysts for enantioselectivealdolreactions in water, on water, and in the presence of water. The presence of
study, affording the aldol product with excellent diastereo- and enantioselectivities, these two catalysts generating opposite enantiomers. Water affects the selectivity, and poor results are obtained under neat reaction conditions or in dry organic solvents. More than three equivalents of water are required for the best diastereo- and enantioselectivities, while three equivalents is the recommended amount