The Catalyst's Logic: A Narrative Review of Enzymology, from Michaelis and Menten to the Ribozymes

Abstract

Enzymes are biochemistry's catalysts: the proteins—and, since Cech and Altman's 1980s ribozymes, the RNAs—whose active sites accelerate the cell's reactions by factors of billions, whose kinetics Michaelis and Menten formalized in 1913, and whose control—allostery's Monod-Wyman-Changeux model, induced fit's Koshland—is the cell's regulation. This article presents a narrative review of the primary literature of enzymology, from Michaelis and Menten's 1913 kinetics and Lineweaver and Burk's 1934 linearization, through Sumner's 1926 crystallization of urease, Koshland's 1958 induced fit, Monod, Wyman, and Changeux's 1965 allosteric model, the ribozyme discoveries of Cech, Zaug, and Grabowski's 1981 and Kruger and colleagues' 1982, Joyce's 2002 RNA world, Koshland's 1995 comparison, Benkovic and Hammes-Schiffer's 2003 catalysis perspective, Fersht's 1999 Structure and Mechanism, and Berg, Tymoczko, and Stryer's 2002 Biochemistry, the codifying textbook. The synthesis is organized around three themes: the kinetic settlement, in which the substrate's saturation became equations and the enzyme became a protein; the control's models, in which specificity's induced fit and allostery's concerted transitions explained the regulation; and the catalytic expansion, in which the ribozymes and the RNA world moved the catalyst's logic beyond protein. It is concluded that enzymology's history is the union of kinetics and structure—one catalyst, described by equations, explained by architecture—and that the ribozyme's discovery made the logic life's oldest.