Sentence examples for base to activate a from inspiring English sources

The subsequent density functional theory (DFT) calculations indicate that a terminal alkoxide (Ot) bound by Zn may work as a general base to activate a water molecule and then a hydroxide derived from the latter performs the initial nucleophilic attack on the phosphor in GB.

Subsequently, Glu-166 acts as a general base to activate a water molecule for deacylation of the enzyme.

Burmeister et al. (2000) reported that Asc is a cofactor for myrosinase and serves as a catalytic base to activate a water molecule without Asc becoming oxidized.

This model is consistent with the mechanism of many other zinc enzymes that use an aspartic acid as a general base to activate a water or hydroxide ion.

The second hydroxyl group on the 4 position of piperidine contacts Asp81, the key active site residue that acts as a base to activate the 1-OH of sphingosine, via a hydrogen bond.

The reaction mechanism proposed for RNase T1 involves E58 acting as a general base to activate the 2′-OH of guanosine for an SN2-type nucleophilic attack on its 3′ phosphate group, H92 (general acid) stabilizing the leaving 5′-OH, and formation of a 2′-3′ cyclic phosphodiester intermediate product (Heinemann and Saenger, 1983).

This Tyr387 is conserved amongst XcOGT and hOGT (Fig.  2a; Clarke et al. 2008) and is in close proximity to Lys388, which could prime the tyrosine to act as a base to activate the acceptor substrate.

The best results were obtained by using complexes with a nucleophilic counter-ion that was capable of acting as a Lewis base to activate the trimethylsilyl cyanide.

The authors observed that the monosodium binaphtholate salt was not an effective catalyst and speculated that the role of disodium binaphtholate might be as a Lewis base to activate the TMSCF3 and form the hexavalent intermediate 271 (Scheme 100).

Given the diametrically different observations on rate acceleration between TMS and DMS enolates and the chloride ion's higher nucleophilicity compared with those of bromide or iodide ions in an aprotic solvent such as DMF, and the low Lewis acidity of CaCl2, 59 chloride ion was determined to function as a Lewis base to activate the DMS enolate.

In the hydrolysis step, the H300 side chain acted as a potential general base to activate the hydrolytic water molecule for nucleophilic attack on the alkyl enzyme intermediate.