Mutation of the tobacco etch virus (TEV) protease nucleophile from cysteine to serine causes an approximately ∼104 -fold loss in activity. Ten rounds of directed evolution of the mutant, TEVSer , overcame the detrimental effects of nucleophile exchange to recover near-wild-type activity in the mutant TEVSer X. Rather than respecialising TEV to the new nucleophile, all the enzymes along the evol...

The nonenzymatic reaction of ATP with a nucleophile to generate ADP and a phosphorylated product proceeds via a dissociative transition state with little bond formation to the nucleophile. Consideration of the dissociative nature of the nonenzymatic transition state leads to the following question: To what extent can the nucleophile be activated in enzymatic phosphoryl transfer? We have address...

We present a density functional theory (B3LYP) study of the isomerization of 4-hydroxybenzylidene-1,2-dimethyl-imidazolinone (HOBDI), which is to mimic the green fluorescent protein (GFP) chromophore, in the ground state promoted by a nucleophile. Four solvents with different polarity, water, DMSO, methanol, and benzene, have been used to characterize the nucleophile assisted mechanism. The for...

the objectives of this experiment were to investigate the application of new ligands including different atoms & evaluation their nucleophile effects against various metals. chemistry researchers are really interested in this field. from among various ligands, there are some ligands with different coordinating ligands as well. there are great number of intermediate complexes and major eleme...

Abstract Catalytic triads, composed of a serine or cysteine nucleophile, histidine, and third triad residue (typically Asp/Glu/Asn), are common in enzyme active sites catalyze wide variety chemical reactions. Two types triads can be distinguished: We refer to them as Nδ‐ Nϵ‐configured, depending on whether the histidine imidazole Nδ Nϵ atom is close nucleophile Oγ/Sγ. In this study, we have ana...

The potassium salt of the boron-centred nucleophile B(CN)32- (1) readily reacts with perfluorinated arenes, such as hexafluorobenzene, decafluorobiphenyl, octafluoronaphthalene and pentafluoropyridine, which results in KF and the K+ salts of the respective borate anions with one {B(CN)3} unit bonded to the (hetero)arene. An excess of K21 leads to the successive reaction of two or, in the case o...

We report a new class of catalytic reaction: the thermal substitution of a secondary and or tertiary alkyl halide with a nitrogen nucleophile. The alkylation of a nitrogen nucleophile with an alkyl halide is a classical method for the construction of C-N bonds, but traditional substitution reactions are challenging to achieve with a secondary and or tertiary alkyl electrophile due to competing ...

Description cPLA2alpha is an 85 kDa protein consisting of 749 amino acids. cPLA2alpha belongs to the alpha-beta hydrolase family which is identified by a characteristic nucleophile elbow with a consensus sequence of Sm-X-Nu-Sm (Sm = small residue, X = any residue and Nu = nucleophile). The protein contains an N-terminal C2 domain (Cadependent, phospholipid binding) and two catalytic domains (al...