825-90-1Relevant articles and documents
OPTICAL FLUORESCENT IMAGING USING CYANINE DYES
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Paragraph 0184; 0188, (2016/06/09)
no abstract published
Promiscuity in antibody catalysis: Esterolytic activity of the decarboxylase 21D8
Backes, Alexander C.,Hotta, Kinya,Hilvert, Donald
, p. 1167 - 1174 (2007/10/03)
The high structural similarity of decarboxylase antibody 21D8 and esterase antibody 48G7 suggests that 21D8 might also possess hydrolytic activity. Kinetic investigations show that 21D8 does promote the selective hydrolysis of methyl 4-nitrophenyl carbonate and sodium 4-(acetoxy)benzenesulfonate with catalytic proficiencies (kcat/Km)/kun of ca. 105 M-1. The ability of 21D8 to accelerate a reaction for which it was not developed suggests that certain antibody scaffolds are intrinsically predisposed toward catalysis, a property that can be enhanced and refined during affinity maturation in response to a transition-state analog. At the same time, however, the restricted structural diversity of the immune system may ultimately limit the catalytic efficiency that can be achieved.
Structure-reactivity correlations in the dissociative hydrolysis of 2′,4′-dinitrophenyl 4-hydroxy-X-benzenesulfonates
Cevasco, Giorgio,Thea, Sergio
, p. 6814 - 6817 (2007/10/03)
The hydrolysis reactions of several title esters in water at 60°C follow the rate law kobs = (ka + kb[OH-])/(1 + αH/Ka), where Ka is the ionization constant of the hydroxy group of the ester and kb is the second-order rate constant for the SN2(S) attack of hydroxide ion on the ionized ester. Hammett and Br?nsted correlations are consistent with a previous proposal that the mechanism related to ka is dissociative. An unusual relationship between ka values and redox equilibrium constants for substituted quinones is found to hold: this finding further supports the dissociative nature of the pathway related to ka.