Nonspecific catalysis by protein surfaces.
Catalytic antibodies are the best available all-around enzyme mimics. They provide a unique experimental approach and some special insights into general questions about catalysis by enzymes. They offer enantiospecific reactions and levels of substrate binding that compare well with typical enzyme reactions, but not--so far--comparable catalytic efficiency. We and others have used the Kemp elimination as a probe of catalytic efficiency in antibodies. We compare these reactions with nonspecific catalysis by other proteins, and with catalysis by enzymes. Several simple reactions are catalyzed by the serum albumins with Michaelis-Menten kinetics, and can be shown to involve substrate binding and catalysis by local functional groups. Here we report the details of one investigation, which implicate known binding sites on the protein surface, and discuss implications for catalyst design and efficiency.
Kirby
A J
AJ
University Chemical Laboratory, Cambridge, UK. ajk1@cam.ac.uk
Hollfelder
F
F
Tawfik
D S
DS
D000818:Animals; D017151:Antibodies, Catalytic / Q000737:chemistry / Q000378:metabolism*; D002384:Catalysis; D006801:Humans; D066298:In Vitro Techniques; D007700:Kinetics; D011506:Proteins / Q000737:chemistry / Q000378:metabolism*; D012709:Serum Albumin / Q000737:chemistry / Q000378:metabolism; D013499:Surface Properties
D017151:Antibodies, Catalytic; D011506:Proteins; D012709:Serum Albumin