ABSTRACT
The industrial application of enzymes that can withstand harsh conditions has greatly increased over the past decade. This is mainly a result of the discovery of novel enzymes from extremophilic microorganisms. Recent advances in the study of extremozymes point to the acceleration of this trend. In particular, enzymes from thermophilic organisms have found the most practical commercial use to date because of their overall inherent stability. This has also led to a greater understanding of stability factors involved in adaptation of these enzymes to their unusual environments.
Subject(s)
Archaea/enzymology , Bacteria/enzymology , Biotechnology , Enzymes/metabolism , Amino Acid Substitution/genetics , Amino Acid Substitution/physiology , Carbohydrates/chemical synthesis , Catalysis , Endopeptidases/chemical synthesis , Endopeptidases/metabolism , Enzyme Stability/physiology , Esterases/chemical synthesis , Esterases/metabolism , Glycoside Hydrolases/chemical synthesis , Glycoside Hydrolases/metabolism , Hydrogen-Ion Concentration , Lipase/chemical synthesis , Lipase/metabolism , Nitriles/metabolism , Osmosis , TemperatureABSTRACT
The use of pH indicators to monitor hydrolase-catalyzed reactions is described. The formation of acid following an enzyme-mediated hydrolysis causes a drop in the pH that can be visualized by a change in the color of the indicator-containing solution. The best indicators are those showing a color transition within the operational pH range of the hydrolases, like bromothymol blue and phenol red. The enantioselectivity of lipases and esterases can be estimated using single isomers under the same conditions and comparing the color turnover for each one. The method has been tested to quickly evaluate the enantioselectivity of a lipase towards a set of ester substrates and applied to the hierarchical screening of a library of thermophilic esterases.
Subject(s)
Chemistry, Organic/methods , Enzymes/metabolism , Hydrolases/chemistry , Indicators and Reagents/chemistry , Acetonitriles/chemistry , Acetonitriles/metabolism , Bromthymol Blue/chemistry , Burkholderia cepacia/enzymology , Catalysis , Chemistry, Organic/instrumentation , Colorimetry/methods , Enzymes/chemistry , Esterases/chemistry , Esterases/metabolism , Hydrogen-Ion Concentration , Hydrolases/metabolism , Peptide Library , Phenolsulfonphthalein/chemistry , Phosphates/chemistry , Potassium Compounds/chemistry , Sensitivity and Specificity , StereoisomerismABSTRACT
Several D-mannosyl phosphate/phosphonate derivatives have been enzymatically prepared as sialyl Lewis x tetrasaccharide mimics, which showed strong-to-moderate inhibition against E-, P-, and L-selectins. The synthesis of these mimics is very straightforward; mannosyl aldehyde derivatives are condensed with dihydroxyacetone phosphate (DHAP) in the presence of a DHAP-dependent aldolase to provide mannosyl phosphates.
Subject(s)
Molecular Mimicry , Oligosaccharides/chemistry , Selectins/drug effects , Carbohydrate Conformation , Fructose-Bisphosphate Aldolase/chemistry , Magnetic Resonance Spectroscopy , Molecular Structure , Oligosaccharides/pharmacology , Sialyl Lewis X AntigenABSTRACT
C2-Symmetrical tetrahydroxyazepanes were synthesized as inhibitors for glycosidases. Tetrahydroxyazepane 1 is a non-specific inhibitor of various glycosidases, while compounds 2, 3 and 4 specifically inhibit beta-N-acetylglucosaminidase, beta-glucosidase, and alpha-fucosidase, respectively, with Ki in the micromolar range. Compound 1 is not an inhibitor of HIV/FIV proteases, but its 3,6-difluorobenzyl derivatives are moderate inhibitors of both enzymes.
