23500-13-2Relevant articles and documents
Nocardiopsins C and D and nocardiopyrone A: New polyketides from an Australian marine-derived Nocardiopsis sp.
Raju, Ritesh,Piggott, Andrew M.,Quezada, Michelle,Capon, Robert J.
, p. 692 - 698 (2013)
A Nocardiopsis sp. (CMB-M0232) recovered from marine sediment collected off the coast of South Molle Island, Queensland, Australia, yielded two new examples of rare prolinyl-macrolactam polyketides, nocardiopsins C (1) and D (2), a new highly substituted α-pyrone polyketide, nocardiopyrone A (3), and the previously reported macrolide polyketides nocardiopsins A (4) and B (5). Structures were assigned on the basis of detailed spectroscopic analysis, degradation, and chemical derivatization. PCR amplification of CMB-M0232 genomic DNA revealed the presence of type I and type II polyketide synthase and nonribosomal peptide synthase domains. 2012 Elsevier Ltd. All rights reserved.
Repurposing the 3-Isocyanobutanoic Acid Adenylation Enzyme SfaB for Versatile Amidation and Thioesterification
Zhu, Mengyi,Wang, Lijuan,He, Jing
supporting information, p. 2030 - 2035 (2020/11/30)
Genome mining of microbial natural products enables chemists not only to discover the bioactive molecules with novel skeletons, but also to identify the enzymes that catalyze diverse chemical reactions. Exploring the substrate promiscuity and catalytic mechanism of those biosynthetic enzymes facilitates the development of potential biocatalysts. SfaB is an acyl adenylate-forming enzyme that adenylates a unique building block, 3-isocyanobutanoic acid, in the biosynthetic pathway of the diisonitrile natural product SF2768 produced by Streptomyces thioluteus, and this AMP-ligase was demonstrated to accept a broad range of short-chain fatty acids (SCFAs). Herein, we repurpose SfaB to catalyze amidation or thioesterification between those SCFAs and various amine or thiol nucleophiles, thereby providing an alternative enzymatic approach to prepare the corresponding amides and thioesters in vitro.
Synthesis of the peptaibol framework of the anticancer agent culicinin D: Stereochemical assignment of the AHMOD moiety
Hung, Kuo-Yuan,Harris, Paul W. R.,Brimble, Margaret A.
, p. 5784 - 5787 (2013/01/15)
The postulated structure of the potent anticancer peptaibol culicinin D has been synthesized using Fmoc-based solid-phase peptide synthesis (SPPS). Comparison of the 1H NMR data for the reported structure of culicinin D with the data obtained for the two synthetic polypeptides epimeric at C-6 in the AHMOD unit established the C-6 stereochemistry of the AHMOD residue in the natural product to be (R).
Functional identification and structure determination of two novel prolidases from cog1228 in the amidohydrolase superfamily
Xiang, Dao Feng,Patskovsky, Yury,Xu, Chengfu,Fedorov, Alexander A.,Fedorov, Elena V.,Sisco, Abby A.,Sauder, J. Michael,Burley, Stephen K.,Almo, Steven C.,Raushel, Frank M.
experimental part, p. 6791 - 6803 (2011/05/05)
Two uncharacterized enzymes from the amidohydrolase superfamily belonging to cog1228 were cloned, expressed, and purified to homogeneity. The two proteins, Sgx9260c (gi|44242006) and Sgx9260b (gi|44479596), were derived from environmental DNA samples originating from the Sargasso Sea. The catalytic function and substrate profiles for Sgx9260c and Sgx9260b were determined using a comprehensive library of dipeptides and N-acyl derivative of l-amino acids. Sgx9260c catalyzes the hydrolysis of Gly-l-Pro, l-Ala-l-Pro, and N-acyl derivatives of l-Pro. The best substrate identified to date is N-acetyl-l-Pro with a value of kcat/Km of 3 × 105 M -1 s-1. Sgx9260b catalyzes the hydrolysis of l-hydrophobic l-Pro dipeptides and N-acyl derivatives of l-Pro. The best substrate identified to date is N-propionyl-l-Pro with a value of kcat/Km of 1 × 105 M-1 s-1. Three-dimensional structures of both proteins were determined by X-ray diffraction methods (PDB codes 3MKV and 3FEQ). These proteins fold as distorted (β/α) 8-barrels with two divalent cations in the active site. The structure of Sgx9260c was also determined as a complex with the N-methylphosphonate derivative of l-Pro (PDB code 3N2C). In this structure the phosphonate moiety bridges the binuclear metal center, and one oxygen atom interacts with His-140. The α-carboxylate of the inhibitor interacts with Tyr-231. The proline side chain occupies a small substrate binding cavity formed by residues contributed from the loop that follows β-strand 7 within the (β/α)8-barrel. A total of 38 other proteins from cog1228 are predicted to have the same substrate profile based on conservation of the substrate binding residues. The structure of an evolutionarily related protein, Cc2672 from Caulobacter crecentus, was determined as a complex with the N-methylphosphonate derivative of l-arginine (PDB code 3MTW).
Enhancement of hydrophobic interactions and hydrogen bond strength by cooperativity: Synthesis, modeling, and molecular dynamics simulations of a congeneric series of thrombin inhibitors
Muley, Laveena,Baum, Bernhard,Smolinski, Michael,Freindorf, Marek,Heine, Andreas,Klebe, Gerhard,Hangauer, David G.
supporting information; experimental part, p. 2126 - 2135 (2010/08/19)
Accurately predicting the binding affinity of ligands to their receptors by computational methods is one of the major challenges in structure-based drug design. One of the potentially significant errors in these predictions is the common assumption that the ligand binding affinity contributions of noncovalent interactions are additive. Herein we present data obtained from two separate series of thrombin inhibitors containing hydrophobic side chains of increasing size that bind in the S3 pocket and with, or without, an adjacent amine that engages in a hydrogen bond with Gly 216. The first series of inhibitors has a m-chlorobenzyl moiety binding in the S1 pocket, and the second has a benzamidine moiety. When the adjacent hydrogen bond is present, the enhanced binding affinity per ?2 of hydrophobic contact surface in the S3 pocket improves by 75% and 59%, respectively, over the inhibitors lacking this hydrogen bond. This improvement of the binding affinity per ?2 demonstrates cooperativity between the hydrophobic interaction and the hydrogen bond.
Enantioselective reactions using two-component chiral phase transfer catalysts in multiphasic systems
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, (2008/06/13)
The present invention provides multiphasic systems comprising at least one chiral selector and an achiral phase transfer catalyst, wherein said system can be used to effect enantioselective reactions or asymmetric induction reactions.
