Biomimetic models for cysteine proteases. 1. Intramolecular imidazole catalysis of thiol ester solvolysis: a model for the deacylation step

Street, J. P.; Brown, R. S.

doi:10.1021/ja00307a043

Cited by 10 publications

(6 citation statements)

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“…34 (tmeda)NiMe 2 35 and (dppe)NiMe 2 (1) 36 were synthesized via a modification of the procedure reported 28 for (dippe)NiMe 2 in which dippe was replaced with tmeda and dppe, respectively. Thioesters, CH 3 C(O)SC 6 H 5 and CH 3 C(O)SC 6 F 5 , were synthesized via a slight modification of the reported procedure 37 with addition of 1 eq. Et 3 N. (Py) 4 NiCl 2 28 was prepared via addition of pyridine to a suspension of anhydrous NiCl 2 in ethyl ether.…”

Section: Experimental Synthesismentioning

confidence: 99%

Synthetic analogs for evaluating the influence of N–H⋯S hydrogen bonds on the formation of thioester in acetyl coenzyme a synthase

et al. 2009

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A series of square planar methylnickel(II) complexes, (dppe)Ni(Me)(SAr) (dppe = 1,2-bis(diphenylphosphino)ethane); 2. Ar = phenyl; 3. Ar = pentafluorophenyl; 4. Ar = o-pivaloylaminophenyl; 5. Ar = p-pivaloylaminophenyl; (depe)Ni(Me)(SAr), (depe = 1,2-bis(diethylphosphino)ethane); 7. Ar = phenyl; 8. Ar = pentafluorophenyl; 9. Ar = o-pivaloylaminophenyl; 10. Ar = p-pivaloylaminophenyl), were synthesized via the reaction of (dppe)NiMe2(1) and (depe)NiMe2(6) with either the corresponding thiol or disulfide. These complexes were characterized by various spectroscopic methods including 31P NMR, 1H NMR, 13C NMR and infrared spectroscopies and in most cases by X-ray diffraction analyses. Solid state and solution measurements establish that 5 and 9 contain intramolecular N-H---S bonds. Carbonylation of the complexes 2-4, 7-10 leads to (dRpe)Ni(CO)2 and MeC(O)SAr via the intermediacy of the acylnickel adducts, (dRpe)Ni(C(O)Me)(SAr), detected at low temperature by 31P NMR spectroscopy. Consistent with experimental observations, density functional theory results reveal that the intramolecular hydrogen bond in 9 stabilizes the acylnickel adduct compared with its non-hydrogen-bonded adduct, 10. Oxidative addition of MeC(O)SC6F5 to (dRpe)Ni(COD) followed by spontaneous decarbonylation proceeds in modest yields generating 3 and 8.

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Section: Experimental Synthesismentioning

confidence: 99%

Synthetic analogs for evaluating the influence of N–H⋯S hydrogen bonds on the formation of thioester in acetyl coenzyme a synthase

et al. 2009

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“…Thus, the results of these studies gave rise to very intense controversies regarding the orientation (axial or equatorial) of the carbomethoxy function of D-KCTI, and hence of enzyme-bound L-APME (203,204). 213 However, one uniquely constrained substrate, 3-methoxycarbonyl-2dibenzazocine-1-one, was synthesized in 1968 by Belleau and Chevalier from diphenic anhydride (205). The reason for this probably lies in the fact that in most of the compounds used, the structural features ofthe normal substrates of a-chymotrypsin are so grossly altered as to cast strong doubts on the validity of the models.…”

Section: Absolute Conformation Of Bound Substratementioning

confidence: 99%

“…A biomimetic model for the deacylation step of papain, a thiol protease, has been developed by following the intramolecular solvolysis ofthio esters by a proximal imidazole group (213). The pH profile of the reaction has a plateau between 7.5 and 10.…”

Section: : Enzyme Chemistrymentioning

confidence: 99%

Bioorganic Chemistry

Dugas¹

1989

Springer Advanced Texts in Chemistry

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“…In the middle eighties the solvolysis of 2-[2-(acetylthio)phenyl]-4,5-dimethylimidazole has been studied in ethanol-water solution as a model for the thiol ester intermediates occurring during the catalytic cycle of cysteine proteases. [20][21][22] All the studied compounds feature one-dimensional networks of hydrogen bonds. Hydrogen bonding interactions play a very important role in functioning of natural systems since hydrogen bonded chains are common proton pathways in biology.…”

Section: Introductionmentioning

confidence: 99%

Imidazolium silanethiolates relevant to the active site of cysteine proteases. A cooperative effect in a chain of NH+⋯S− hydrogen bonds

et al. 2012

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Three imidazolium silanethiolates relevant to the active site of cysteine proteases have been synthesized and investigated by X-ray diffraction, IR spectroscopy and computational methods. As indicated by crystallographic and FT-IR data in the solid state, the transfer of proton from thiol to imidazole takes place and a thiolato-imidazolium ion pair is formed. The FT-IR spectra of crystalline imidazolium silanethiolates exhibit intense continua characteristic for systems containing highly polarizable protons. DFT and ab initio HF calculations confirm the transfer of proton and prove the cooperativity of hydrogen bonds in the studied systems.

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Biomimetic models for cysteine proteases. 1. Intramolecular imidazole catalysis of thiol ester solvolysis: a model for the deacylation step

Cited by 10 publications

References 0 publications

Synthetic analogs for evaluating the influence of N–H⋯S hydrogen bonds on the formation of thioester in acetyl coenzyme a synthase

Synthetic analogs for evaluating the influence of N–H⋯S hydrogen bonds on the formation of thioester in acetyl coenzyme a synthase

Bioorganic Chemistry

Imidazolium silanethiolates relevant to the active site of cysteine proteases. A cooperative effect in a chain of NH+⋯S− hydrogen bonds

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