Hyperbolic catalytic inhibition

Fingerprints of HCaI: Dependence of the parameters on [X]
Fingerprints of HCaI: Specific velocity plot and replot

Featured examples

  • Km↓         The apparent Michaelis constant decreases with increasing [X]
  • V  (∴kcat )      The apparent limiting rate, and therefore the catalytic constant, decrease with increasing [X]
  • (V/Km)⫫ (∴kcat/Km ⫫)  The apparent V/Km ratio, and therefore the specificity constant, are independent of [X]

These symbols are shown only when the featured dependencies of the parameters on modifier concentration have been demonstrated by the authors.

EC no.ModifierSubstrate(1)Name given by authors (2)Reference(3)
1Glutamate dehydrogenase (NAD(P)+)
Not specified inhibitory behavior. Clear diagnosis, parameters impreciseFrieden
(1962, 1963)
2Cathepsin K
Homo sapiens 7Cbz-Phe-Arg-7-amino-4-methylcoumarylamideHyperbolic uncompetitive inhibition
α = β = 0.19, KX = 0.29 mM
3Cathepsin K
Homo sapiens 8Cbz-Phe-Arg-7-amino-4-methylcoumarylamideHyperbolic uncompetitive inhibition
α = β = 0.31, KX = 1.1 mM
4Penicillin amidase
Escherichia coli ATC11105 (4)p-dimethylamino-benzaldehydeHyperbolic uncompetitive inhibition
α = β = 0.28, KX = 142 mM
5Penicillin amidase
Escherichia coli ATC11105 (4)p-dimethylamino-benzaldehydeHyperbolic uncompetitive inhibition
α = β = 0.34, KX = 30.7 mM
6Penicillin amidase
Escherichia coli ATC11105,000 (4)p-dimethylamino-benzaldehydeHyperbolic uncompetitive inhibition
α = β = 0.17, KX = 45.8 mM
7Glutathione-disulfide reductase
Saccharomyces cerevisiae OL-Glutathione (oxidized)Hyperbolic uncompetitive inhibition
α = β = 0.15, KX = 500 μM
8Glutathione-disulfide reductase
Saccharomyces cerevisiae OL-Glutathione (oxidized)Hyperbolic uncompetitive inhibition
α = β = 0.15, KX = 0.4 μM
9Glutathione-disulfide reductase
Saccharomyces cerevisiae,8-quinolinedione (5)L-Glutathione (oxidized)Hyperbolic uncompetitive inhibition
α = β = 0.14, KX = 14 μM
10Glutathione-disulfide reductase
Saccharomyces cerevisiae,4-naphthoquinoneL-Glutathione (oxidized)Hyperbolic uncompetitive inhibition
α = β = 0.19, KX = 21 μM
11Xanthine oxidase
Bos taurus (substrate)O2Hyperbolic uncompetitive inhibition (6)Morpeth
12NADH:ubiquinone reductase (non-electrogenic)
Saccharomyces cerevisiae uncompetitive inhibition
α = β < 1, KX = 5.4 μM
134-Hydroxy-tetrahydro-dipicolinate synthase
Escherichia coli mixed inhibition
α = β = 0.046, KX = 3.9 mM
14Cathepsin B
Homo sapiens bisphosphinic complexCbz-Phe-Arg-7-amino-4-methylcoumarylamide Hyperbolic mixed type inhibition
Km↓, V↓, and α = β = 0.18-0.19
Homo sapiens fragment Tos-Gly-Pro-Arg-7-amino-4-methylcoumarylamideHyperbolic uncompetitive inhibition
α = β = 0.49, KX = 0.71 μM
16Lipopolysaccharide heptosyltransferase I
Escherichia coli
2.4.99.B6Hexene-beta-D-glucopyranosideO-deacylated E. coli Kdo2-Lipid AUncompetitive inhibition (7)
Km↓, V↓, (V/Km)⫫

(1) Always the varied substrate. In two- or more-substrate reactions the concentration(s) of the non varied substrate(s) is/are kept constant.

(2) Name of the mechanism given by the authors in the quoted reference. α, β and the inhibition/activation constants for the modifier (X), uniformly denoted KX, are the values specified by the authors. In some cases,  missing parameters have been calculated from graphical or tabular data provided in the papers. In two- or more-substrate reactions, KX represents an apparent constant at given concentrations of the fixed substrates and no calculations of the intrinsic values have been attempted.

(3) Full references at the end of the page provide also the digital object identifier (doi), if available. Clicking the authors (highlighted) opens the reference in PubMed.

(4) PEG-400, PEG-4000, PEG-10,000 = polyethylene glycol with molecular mass.

(5) In the referred paper, the molecule with the LY83583 acronym.

(6) Substrate inhibition.

(7) The measurements were performed with only three modifier concentrations (10, 100 and 1000 μM), which are barely sufficient for diagnosing the mechanism but inadequate for parameter calculations.


  1. Bincoletto C, Tersariol ILS, Oliveira CR, Dreher S, Fausto DM, Soufen MA, Nascimento FD, Caires ACF (2005) Chiral cyclopalladated complexes derived from N,N-dimethyl-1-phenethylamine with bridging bis(diphenylphosphine)ferrocene ligand as inhibitors of the cathepsin B activity and as antitumoral agents. Bioorg Med Chem 13: 3047-3055. doi:10.1016/j.bmc.2005.01.057
  2. Dobson RCJ, Griffin MDW, Roberts SJ, Gerrard JA (2004) Dihydrodipicolinate synthase (DHDPS) from Escherichia coli displays partial mixed inhibition with respect to its first substrate, pyruvate. Biochimie 86: 311-315. doi:10.1016/j.biochi.2004.03.008
  3. Frieden C (1962) The unusual inhibition of glutamate dehydrogenase by guanosine di- and triphosphate. Biochim Biophys Acta 59: 484-486. doi:10.1016/0006-3002(62)90204-4
  4. Frieden C (1963) Glutamate dehydrogenase. V. The relation of enzyme structure to the catalytic function. J Biol Chem 238: 3286-3299.
  5. Kazan D, Erarslan A (1997) Stabilization of Escherichia coli penicillin G acylase by polyethylene glycols against thermal inactivation. Appl Biochem Biotechnol 62: 1-13. doi:10.1007/BF02787979
  6. Lüönd RM, McKie JH, Douglas KT, Dascombe MJ, Vale J (1998) Inhibitors of glutathione reductase as potential antimalarial drugs. Kinetic cooperativity and effect of dimethyl sulphoxide on inhibition kinetics. J Enzyme Inhib 13: 327-345. doi:10.3109/14756369809021479
  7. Morpeth FF (1983) Studies on the specificity toward aldehyde substrates and steady-state kinetics of xanthine oxidase. Biochim Biophys Acta 744: 328-334. doi:10.1016/0167-4838(83)90207-8
  8. Nkosana NK, Czyzyk DJ, Siegel ZS, Cote JM, Taylor EA (2018) Synthesis, kinetics and inhibition of Escherichia coli Heptosyltransferase I by monosaccharide analogues of Lipid A. Bioorg Med Chem Lett 28: 594-600. doi:10.1016/j.bmcl.2018.01.040
  9. Novinec M, Lenarčič B, Baici A (2014) Probing the activity modification space of the cysteine peptidase cathepsin K with novel allosteric modifiers. PLoS One 9: e106642. doi:10.1371/journal.pone.0106642
  10. Schmitz T, Rothe M, Dodt J (1991) Mechanism of the inhibition of a-thrombin by hirudin-derived fragments hirudin(1-47) and hirudin(45-65). Eur J Biochem 195: 251-256. doi:10.1111/j.1432-1033.1991.tb15701.x
  11. Velázquez I, Pardo JP (2001) Kinetic characterization of the rotenone-insensitive internal NADH: ubiquinone oxidoreductase of mitochondria from Saccharomyces cerevisiae. Arch Biochem Biophys 389: 7-14. doi:10.1006/abbi.2001.2293