The Hydrolysis of p-Nitrophenyl Acetate Catalyzed by 3-Phosphoglyceraldehyde Dehydrogenase

The Amino Acid Sequence of a Hexapeptide Containing an Essential Sulfhydryl Group of Rabbit Muscle Glyceraldehyde-3-Phosphate Dehydrogenase*

“…Earlier studies with rabbit muscle glyceraldehyde-3-phosphate dehydrogenase had indicated that not all the sulfhydryl groups present in the molecule are essential for activity (Segal and Boyer, 1953;Boyer and Segal, 1954). There is ample evidence for the existence of three or four active sites per molecule, each containing at least one essential sulfhydryl group (Koeppe et al, 1956;Velick, , 1958Segal and Boyer, 1953;Boyer and Segal, 1954;Racker et al, 1959;Park et al, 1961). The fact that stoichiometric quantities of DDPM reacted preferentially with the sulfhydryl groups at the active centers (Segal and Gold, 1963) greatly facilitated the labeling of these moieties.…”

Rapid specialization of counter defenses enables two-spotted spider mite to adapt to novel plant hosts

“…Twenty, 10, and 10 µg of protein per reaction were used for measuring the enzymatic activity of GSTs, P450s, and esterases, respectively. The enzymatic activities were assessed spectrophotometrically using 1-chloro-2,4-dinitrobenzene (for GSTs; Habig and Jakoby, 1981 ), 7-ethoxy-4-trifluoromethylcoumarin (for P450s) ( Buters et al, 1993 ), and 4-nitrophenyl acetate (for esterases; Park et al, 1961 ), as substrates. For GST and esterases, the linearity of the reaction was determined by plotting the absorbance values against time over a 5 min period and calculation of sample activity was performed in the linear range.…”

Rapid specialization of counter defenses enables two-spotted spider mite to adapt to novel plant hosts

“…Twenty, 10, and 10 μg of protein per reaction were used for measuring the enzymatic activity of glutathione-S-transferases (GSTs), P450 monooxygenases, and esterases, respectively. The enzymatic activities were assessed spectrophotometrically using 1-chloro-2,4-dinitrobenzene (CDNB) (for GSTs) (Habig and Jakoby, 1981), 7-ethoxy-4-trifluoromethylcoumarin (7-EFC) (for P450s) (Buters et al ., 1993), and 4-nitrophenyl acetate (pNPA) (for esterases) (Park et al ., 1961), as substrates. For GST and esterases, the linearity of the reaction was determined by plotting the absorbance values against time over 5 minutes period and calculation of samples activity was performed in the linear range.…”