Open AccessNew Methods for the Study of Complex Enzyme Kinetics Illustrated by Analysis of the Wavy Curves of ν versus [S] and Non‐linear Double‐Reciprocal Plots for Human‐Placental 15‐Hydroxyprostaglandin Dehydrogenase
Author(s) -
BARDSLEY William G.,
CRABBE M. J. C.
Publication year - 1976
Publication title -
european journal of biochemistry
Language(s) - English
Resource type - Journals
eISSN - 1432-1033
pISSN - 0014-2956
DOI - 10.1111/j.1432-1033.1976.tb10849.x
Subject(s) - reciprocal , nad+ kinase , kinetics , dehydrogenase , rate equation , chemistry , degree (music) , enzyme , mathematics , physics , biochemistry , philosophy , classical mechanics , linguistics , acoustics
A new method for discovering the minimum degree of rate equations using only the experimental graphs and a straight‐edge (transparent ruler) is presented. This method is then illustrated by an analysis of the wavy ν vs [S] curves and non‐linear double‐reciprocal plots reproducibly given by NAD‐dependent 15‐hydroxyprostaglandin dehydrogenase for which a new improved purification is described. It is shown by this analysis that the enzyme has a complex mechanism involving cooperatively linked dependent sites and requiring a rate equation of at least fourth degree in prostaglandin and NAD + with no kinetically significant dead‐end complexes.