Effect of the Addition of a Nonaqueous Polar Solvent (Glycerol) on Enzymatic Catalysis in Reverse Micelles. Hydrolysis of 2-Naphthyl Acetate by α-Chymotrypsin

Langmuir ◽  
2004 ◽  
Vol 20 (14) ◽  
pp. 5732-5737 ◽  
Author(s):  
R. Darío Falcone ◽  
M. Alicia Biasutti ◽  
N. Mariano Correa ◽  
Juana J. Silber ◽  
Eduardo Lissi ◽  
...  
Keyword(s):  
Reverse Micelles ◽  
Polar Solvent ◽  
Enzymatic Catalysis ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

Cationic Reverse Micelles Create Water with Super Hydrogen-Bond-Donor Capacity for Enzymatic Catalysis: Hydrolysis of 2-Naphthyl Acetate by α-Chymotrypsin

2010 ◽  
Vol 16 (29) ◽  
pp. 8887-8893 ◽  
Author(s):  
Fernando Moyano ◽  
R. Dario Falcone ◽  
J. C. Mejuto ◽  
Juana J. Silber ◽  
N. Mariano Correa
Keyword(s):  
Hydrogen Bond ◽  
Reverse Micelles ◽  
Enzymatic Catalysis ◽  
Hydrogen Bond Donor ◽  
Donor Capacity ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

scholarly journals Kinetics of the alkaline hydrolysis of crystal violet in micelles, reverse micelles and microemulsions of cetyltrimethylammonium bromide

1970 ◽  
Vol 24 (2) ◽  
pp. 173-184 ◽  
Author(s):  
Ferdousi Begum ◽  
Md Yousuf A Molla ◽  
M Muhibur Rahman ◽  
Md Abu Bin Hasan Susan
Keyword(s):  
Crystal Violet ◽  
Alkaline Hydrolysis ◽  
Reverse Micelles ◽  
Cetyltrimethylammonium Bromide ◽  
Specific Conductivity ◽  
Water System ◽  
Chemical Society ◽  
Order Rate Constant ◽  
Kinetics Of ◽  
Hydrolysis Of

Kinetics of the alkaline hydrolysis of crystal violet (CV) in micelles, reverse micelles and microemulsions of a cationic surfactant, cetyltrimethylammonium bromide (CTAB) was studied at 25 ± 0.1 oC using spectrophotometric method. The rate of alkaline hydrolysis of CV was catalyzed by micellar solutions of CTAB. The pseudo first order rate constant (k') has been found to decrease upon incorporation of 1-butanol to cationic CTAB micelles, which displaces the substrate from the micellar into the aqueous phase. In CTAB/cyclohexane/1-butanol/water system, as the content of 1-butanol increases, specific conductivity and density of the microemulsions and reverse micelles decrease. The change in physical properties also causes change in reaction environment. A change from a micelle-rich (o/w) to a reverse micelle-rich (w/o) condition is apparent for microemulsions and consequently the k' vs. % wt. of 1-butanol profiles show an initial decrease in the k' followed by a gradual increase and finally, to a sharp increase with increasing 1-butanol content. Microemulsions and reverse micelles thus offer the potential to control rate of a reaction by formation of micelles in water phase and reverse micelles in oil phase. DOI: http://dx.doi.org/10.3329/jbcs.v24i2.9706 Journal of Bangladesh Chemical Society, Vol. 24(2), 173-184, 2011

Detection of esterase activity in susceptible and organophosphate resistant strains of the cattle tick Boophilus microplus (Acari: Ixodidae)

1997 ◽  
Vol 87 (2) ◽  
pp. 197-202 ◽  
Author(s):  
R. Rosario-Cruz ◽  
E. Miranda-Miranda ◽  
Z. Garcia-Vasquez ◽  
M. Ortiz-Estrada
Keyword(s):  
Esterase Activity ◽  
Boophilus Microplus ◽  
Cattle Tick ◽  
Molecular Weights ◽  
Sds Page ◽  
Genes Encoding ◽  
Resistant Strains ◽  
Hydrolysis Of ◽  
Coomassie Brilliant ◽  
Naphthyl Acetate

AbstractTwo organophosphate (OP) resistant strains of the cattle tick Boophilus microplus (Canestrini) from Mexico and Costa Rica were used to analyse the presence of esterase activity associated with resistance. The concentrations of six major proteins in both resistant strains were increased compared to the susceptible Morelos strain, both when stained with Coomassie Brilliant Blue after SDS-PAGE, and when analysed for esterase activity by the hydrolysis of naphthyl acetate esters. Esterases were named A or B in relation to the substrate preference for alpha or beta naphthyl acetate and numbered according to their position on the SDS—PAGE. The molecular weights of these proteins were: 125, 115, 108, 77, 43 and 67 Kd for Est-Bl, Est-B2, Est-B3, Est-B4, Est-B5 and Est-A respectively. Est-B3 showed cholinesterase (ChE) activity. This study strengthens the hypothesis that the mechanism associated with OP resistance found in many other insects includes an increase of esterase activity, probably as a result of gene amplification. The genes encoding these enzymes could be potentially used as molecular markers to detect resistance in the cattle tick B. microplus using a DNA probe.

A Kinetic Study of the Aminolysis and Hydrolysis of α-Naphthyl Acetate

1955 ◽  
Vol 77 (10) ◽  
pp. 2771-2773 ◽  
Author(s):  
Peter J. Hawkins ◽  
Ivan Piscalnikow
Keyword(s):  
Kinetic Study ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

scholarly journals Acid Hydrolysis of Bromazepam Catalyzed by Micelles, Reverse Micelles, and Microemulsions

2015 ◽  
Vol 2015 ◽  
pp. 1-10
Author(s):  
Ferdousi Begum ◽  
M. Yousuf A. Mollah ◽  
M. Muhibur Rahman ◽  
Md. Abu Bin Hasan Susan
Keyword(s):  
Physicochemical Properties ◽  
Acid Hydrolysis ◽  
Reverse Micelles ◽  
Cetyltrimethylammonium Bromide ◽  
Order Rate Constant ◽  
Excellent Correlation ◽  
Initial Decrease ◽  
Droplet Sizes ◽  
Kinetics Of ◽  
Hydrolysis Of

Kinetics of the acid hydrolysis of bromazepam (Bz) has been investigated in micelles, reverse micelles, and microemulcions of cetyltrimethylammonium bromide (CTAB) by spectrophotometric method. The rate of the acid hydrolysis of Bz was found to be enhanced both below and above the critical micelle concentration (CMC) of CTAB in aqueous solution. The pseudo-first-order rate constant (k′) shows an initial decrease for both low and high H+concentrations. With further increase in [CTAB], at low [H+], thek′attains an almost constant value, while, at high [H+], thek′passes through a maximum and then decreases. The kinetic data for catalysis by micelles of CTAB was interpreted with the pseudophase ion exchange (PIE) model. In CTAB/cyclohexane/1-butanol/water microemulsions, as the water to surfactant ratio (wo) increases, the physicochemical properties and droplet sizes of microemulsions significantly change and distinct changes in reaction environment can be marked. The rate of the hydrolysis reaction exhibits excellent correlation with the physicochemical properties and droplet sizes of the microemulsions and reverse micelles of CTAB. At [H+] = 0.001 M, in reverse micelles and microemulsions of CTAB, thek′of the acid hydrolysis of Bz decreases sharply followed by a slight increase with increasingwo.

scholarly journals Preparation of Metal Oxide Ultrafine Particles by Hydrolysis of Metal Alkoxide in Reverse Micelles.

1992 ◽  
Vol 18 (3) ◽  
pp. 296-302 ◽  
Author(s):  
Takayuki Hirai ◽  
Eiji Imamura ◽  
Takayoshi Matsumoto ◽  
Ryoichi Kuboi ◽  
Isao Komasawa
Keyword(s):  
Metal Oxide ◽  
Reverse Micelles ◽  
Ultrafine Particles ◽  
Metal Alkoxide ◽  
Hydrolysis Of

Malathion-specific resistance in a strain of the rust red grain beetle Cryptolestes ferrugineus (Coleoptera: Cucujidae)

1998 ◽  
Vol 88 (2) ◽  
pp. 199-206 ◽  
Author(s):  
A.G. Spencer ◽  
N.R. Price ◽  
A. Callaghan
Keyword(s):  
Resistant Strain ◽  
Specific Resistance ◽  
Strain Differences ◽  
Gas Chromatography Mass Spectrometry ◽  
Cryptolestes Ferrugineus ◽  
Tributyl Phosphorotrithioate ◽  
Inhibition Studies ◽  
Hydrolysis Of ◽  
Naphthyl Acetate

AbstractA strain of Cryptolestes ferrugineus (Stephens) bred for malathion-specific resistance was found to be 650 fold resistant at LD50 when compared with a susceptible strain bred from the same stock. Resistance was more than 98% synergized by triphenyl phosphate and S,S,S-tributyl phosphorotrithioate, but unaffected by piperonyl butoxide. AChE inhibition by malaoxon varied slightly between the strains. Non-specific esterase activity as measured by the hydrolysis of α-naphthyl acetate was slightly reduced in the resistant strain whereas there were no inter-strain differences in the hydrolysis of β-naphthyl acetate. Products of in vitro metabolism of malathion were identified by thin-layer chromatography and gas chromatography-mass spectrometry as α- and β-malathion mono-acids. It was therefore concluded that resistance was due to the hydrolytic breakdown of malathion by a malathion-specific carboxylesterase. The rate of in vitro malathion hydrolysis was found to be 31 times greater in the resistant strain. In vitro inhibition studies indicated that resistance is attributable to a carboxylesterase unique to the resistant strain. The implications of these results are discussed in relation to work recently carried out on malathion-specific resistance in dipterous species.

Sign in / Sign up

Export Citation Format

Share Document