166734-64-1Relevant academic research and scientific papers
Calorimetric Evaluation of Enzyme Kinetic Parameters
Williams, Brent A.,Toone, Eric J.
, p. 3507 - 3510 (1993)
The measurement of kinetic parameters (kcat, Km, Ki) for a wide range of proteolytic enzymes is vital to contemporary bioorganic and medicinal chemistry.Enzyme assays based on changes in optical properties of the system or changes in concentration of an ion detectable electrochemically are not viable for many enzyme-catalyzed reactions, including proteases and peptidases.Hydrolysis of an amide bond produces no change in the optical properties or pH of the reaction solution, and as a result no general direct method for the evaluation of protease kinetics exists using underivatized substrates.We report here a microcalorimetric assay which provides a general and straightforward technique for the measurement of kinetic parameters of hydrolysis of underivatized peptide substrates by proteases.Using this technique, kcat values as high as 105 s-1 can be easily measured.We demonstrate the utility of the technique by measuring the kinetics of hydrolysis of several N-acylamino acids by the synthetically useful enzyme hog kidney acylase and the hydrolysis of tetrapeptide p-nitrophenyl anilides by subtilisin BPN'.Although we have used the technique to monitor amide bond hydrolysis, the methodology is applicable to any system with appropriate kinetic and thermodynamic properties.
Reversibly switching the conformation of short peptide through in-tether chiral sulfonium auxiliary
Shi, Xiaodong,Jiang, Yixiang,Yang, Dan,Zhao, Hui,Tian, Yuan,Li, Zigang
, p. 485 - 488 (2018)
A chirality induced helicity method has been developed to modulate the peptide's biophysical and biochemical properties. We report herein a novel approach for reversibly switching the conformation of short constraint α-helical peptides through alkylation of the in-tether thioether and dealkylation of the chiral sulfonium. This traceless redox sensitive tagging strategy broadened our scope of CIH (chirality induced helicity) strategy and provided a valuable approach to functionalize the peptide tether.
Improved synthesis of unnatural amino acids for peptide stapling
Li, Bo,Zhang, Jie,Xu, Yongjuan,Yang, Xiaoxiao,Li, Li
, p. 2374 - 2377 (2017/05/29)
The procedures for the synthesis of various α-alkenyl and alkyne amino acids were systematically optimized in light of enhancing atom economy, reducing hazardous reagent usage, and simplifying workup. By starting with Boc-Pro-OH and coupling with EDCI/DMAP followed by alkylation, chiral auxiliary was synthesized with high yield and enantioselectivity. For alkylation of the chiral complex, tBuONa was found and proved by quantitative calculation to be superior to tBuOK in generating more nucleophilic enolate salt, thereby can significantly enhance yield under room temperature. Final Fmoc protection was also dramatically facilitated in one-pot sequential manner by adding EDTA-2Na as the nickel chelator. Synthesis of α-bisalkenyl amino acid was also accomplished by achiral complex approach with high yield and efficacy. Accordingly, five most commonly used N-Fmoc protected α-alkenyl and alkynyl amino acids were synthesized and characterized.
An in-tether sulfilimine chiral center induces helicity in short peptides
Lin, Huacan,Jiang, Yixiang,Zhang, Qingzhou,Hu, Kuan,Li, Zigang
supporting information, p. 10389 - 10391 (2016/09/02)
A precisely positioned sulfilimine chiral center in the tether of a stabilized peptide would determine the peptide's secondary structure. Peptide sulfilimines could be prepared by a facile chloramine T oxidation and the two resulting peptide diastereomers showed significant differences in their secondary structures, which were supported by circular dichroism spectroscopy and NMR.
Influence of α-methylation in constructing stapled peptides with olefin metathesis
Zhang, Qingzhou,Shi, Xiaodong,Jiang, Yanhong,Li, Zigang
, p. 7621 - 7626 (2014/12/11)
Ring-closing metathesis is commonly utilized in peptide macro-cyclization. The influence of α-methylation of the amino acids bearing the olefin moieties has never been systematically studied. In this report, controlled reactions unambiguously indicate that α-methylation at the N-terminus of the metathesis sites is crucial for this reaction to occur. Also, we first elucidated that the E-isomers of stapled peptides are significantly more helical than the Z-isomers.
Robust asymmetric synthesis of unnatural alkenyl amino acids for conformationally constrained α-helix peptides
Aillard, Boris,Robertson, Naomi S.,Baldwin, Adam R.,Robins, Siobhan,Jamieson, Andrew G.
supporting information, p. 8775 - 8782 (2014/12/11)
The efficient asymmetric synthesis of unnatural alkenyl amino acids required for peptide 'stapling' has been achieved using alkylation of a fluorine-modified NiII Schiff base complex as the key step.
Monosubstituted alkenyl amino acids for peptide "stapling"
Yeo, David J.,Warriner, Stuart L.,Wilson, Andrew J.
supporting information, p. 9131 - 9133 (2013/09/24)
Alkenylglycine amino acids were assessed as potential candidates for hydrocarbon stapling and shown to be effective in stapling of the BID BH3 peptide.
Large scale enantiomeric synthesis, purification, and characterization of ω-unsaturated amino acids via a Gly-Ni(II)-BPB-complex
Gu, Xuyuan,Ndungu, John M.,Qiu, Wei,Ying, Jinfa,Carducci, Michael D.,Wooden, Hank,Hruby, Victor J.
, p. 8233 - 8243 (2007/10/03)
The enantiomeric syntheses of ω-unsaturated amino acids and β-substituted ω-unsaturated amino acids were accomplished by using Gly-Ni-2[N-(N′-benzylprolyl)amino]benzophenone (BPB) as a chiral auxiliary. The synthesis provides excellent yields and high diastereoselectivities. The product crystallization followed by isomer epimerization strategy makes the reaction practical and useful for large-scale preparations. Dialkylation of the Ni(II)-complex, which was designed for mechanistic considerations, revealed that high diastereoselectivity is obtained due to the thermodynamic conformational stability of the Ni(II)-complex. The assignment of absolute configuration was accomplished by NMR, which is supported by corresponding X-ray structure and optical rotation data. Both enantiomerically pure amino acids can be synthesized in this alkylation-hydrolysis two-step strategy in multi gram scales.
A Biocatalytic Route to Enantiomerically Pure Unsaturated α-H-α-Amino Acids
Wolf, Larissa B.,Sonke, Theo,Tjen, Kim C. M. F.,Kaptein, Bernard,Broxterman, Quirinus B.,Schoemaker, Hans E.,Rutjes, Floris P. J. T.
, p. 662 - 674 (2007/10/03)
A set of both enantiomeric forms of non-proteinogenic, unsaturated α-H-α-amino acids was efficiently synthesized using a biocatalytic pathway. This route involved the straightforward synthesis of the required unsaturated amino acid amides, followed by resolution with an aminopeptidase present in Pseudomonas putida ATCC 12633 and/or a genetically modified organism, leading to the (S)-acids and (R)-amides. Undesired amino acid racemase activity was identified in the wild-type strain, which was absent in the newly developed organism. The (R)-amides were hydrolyzed under mild conditions using an amidase present in whole cells from Rhodococcus erythropolis NCIMB 11540 to the (R)-acids. The viability of this procedure was demonstrated with the multi-gram synthesis of a variety of unsaturated amino acids in excellent enantiopurity.
Synthesis and evaluation of ω-borono-α-amino acids 1 as active-site probes of arginase and nitric oxide synthases
Collet, Sylvain,Carreaux, Francois,Boucher, Jean-Luc,Pethe, Stephanie,Lepoivre, Michel,Danion-Bougot, Renee,Danion, Daniel
, p. 177 - 182 (2007/10/03)
Enantiomerically pure ω-borono-α-amino acids of various chain lengths have been synthesized according to a general methodology involving condensation of alkenyl and alkynyl bromides with NiII complex of the Schiff base derived from glycine and (S)-2-[N′-(N-benzylprolyl)amino]benzophenone, hydroboration of the intermediate ω-unsaturated α-amino acids with diisopinocampheylborane, and oxidation with acetaldehyde. Some of these compounds act as potent inhibitors of rat liver and murine macrophage arginases, demonstrating that distance between the B(OH)2 and α-amino acid groups is a key determinant for their interaction with arginase. In contrast, they are without effect on neuronal and inducible NO synthases. The Royal Society of Chemistry 2000.
