HMx(Sp = Ca)I – Kinetic Mechanisms of Enzyme Inhibition and Activation

Hyperbolic mixed, balanced inhibition

**Fingerprints of HMx(Sp=Ca)I: Dependence of the parameters on [X]**

**Fingerprints of **HMx(Sp=Ca)I**: Specific velocity plot and replots**

Featured examples

#	Enzyme Species	EC no.	Modifier	Substrate⁽¹⁾	Name given by authors ⁽²⁾	Reference⁽³⁾
1	Leukocyte elastase Homo sapiens	3.4.21.37	Pentosan polysulfate	t-Butyloxycarbonyl-Ala- p-nitrophenyl ester	Hyperbolic noncompetitive inhibition α = 1, β = 0.4, K_X = 0.18 μM	Baici (1981)
2	4-Hydroxy-tetrahydro-dipicolinate synthase Escherichia coli	4.3.3.7	Lysine	(S)-aspartate-β-semialdehyde	Partial noncompetitive inhibition α = 1, β = 0.09, K_X = 0.32 mM	Dobson (2004)
3	Plasmin Homo sapiens	3.4.21.7	Modified dextran RG1503 ⁽⁴⁾	(D)-Val-Leu-Lys-p-nitroanilide	Hyperbolic noncompetitive inhibition α = 1, β = 0.62, K_X = 110 nM	Ledoux (2000)
4	Plasmin Homo sapiens	3.4.21.7	Modified dextran RG1192 ⁽⁵⁾	(D)-Val-Leu-Lys-p-nitroanilide	Hyperbolic noncompetitive inhibition α = 1, β = 0.2, K_X = 290 nM	Ledoux (2000)
5	NADH:ubiquinone reductase (non-electrogenic) Saccharomyces cerevisiae	1.6.5.9	Flavone ⁽⁶⁾	DCPIP ⁽⁷⁾	Hyperbolic noncompetitive inhibition α = 1, β < 1, K_X = 7 μM	Velázquez (2001)
6	Acetylcholinesterase Torpedo californica	3.1.1.7	d-Tubocurarine	7-acetoxy-4-methylcoumarin	Nonlinear noncompetitive inhibition α = 1, β < 1, K_X = 85 μM	Berman (1990)
7	Spermidine synthase Bos taurus	2.5.1.16	5'-Methythioadenosine	Putrescine	Hyperbolic mixed-type inhibition K_ic = K_iu = 10-20 μM ⁽⁸⁾	Raina (1984)
8	Spermidine synthase Bos taurus	2.5.1.16	5'-Methythioadenosine	Decarboxylated adenosylmethionine	Hyperbolic mixed-type inhibition K_ic = K_iu = 20 μM ⁽⁸⁾	Raina (1984)
9	Non-specific serine/ threonine protein kinase Rattus norvegicus	2.7.11.1	Heparin fragment (20-mer)	Peptide RRRADDSDDDDD	Hyperbolic partial non-competitive mixed type inhibition α = 1, β = 0.17, K_X = 0.13 μM	O'Farrel (1999)
10	Caspase-1 Homo sapiens	3.4.22.36	NSC321205	Acetyl-Tyr-Val-Ala-Asp-7-amino-4-trifluoromethylcoumarylamide	Partial noncompetitive inhibition α = 0.90, β = 0.25, K_X = 1.02 μM	Feldman (2012)
11	Caspase-1 Homo sapiens	3.4.22.36	NSC277584	Acetyl-Tyr-Val-Ala-Asp-7-amino-4-trifluoromethylcoumarylamide	Partial noncompetitive inhibition α = 1.02, β = 0.60, K_X = 0.44 μM	Feldman (2012)
12	Caspase-1 Homo sapiens	3.4.22.36	NSC321206	Acetyl-Tyr-Val-Ala-Asp-7-amino-4-trifluoromethylcoumarylamide	Partial noncompetitive inhibition α = 0.99, β = 0.34, K_X = 0.80 μM	Feldman (2012)
13	Caspase-1 Homo sapiens	3.4.22.36	NSC310547	Acetyl-Tyr-Val-Ala-Asp-7-amino-4-trifluoromethylcoumarylamide	Partial noncompetitive inhibition α = 1.01, β = 0.46, K_X = 0.56 μM	Feldman (2012)
14	Caspase-3 Homo sapiens	3.4.22.56	NSC321205	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 1.06, β = 0.14, K_X = 0.35 μM	Feldman (2012)
15	Caspase-3 Homo sapiens	3.4.22.56	NSC277584	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 0.94, β = 0.14, K_X = 0.71 μM	Feldman (2012)
16	Caspase-3 Homo sapiens	3.4.22.56	NSC321206	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 0.99, β = 0.19, K_X = 0.67 μM	Feldman (2012)
17	Caspase-3 Homo sapiens	3.4.22.56	NSC310547	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 1.06, β = 0.28, K_X = 0.95 μM	Feldman (2012)
18	Caspase-8 Homo sapiens	3.4.22.61	NSC321205	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 0.98, β = 0.23, K_X = 0.69 μM	Feldman (2012)
19	Caspase-8 Homo sapiens	3.4.22.61	NSC277584	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 1.04, β = 0.11, K_X = 0.28 μM	Feldman (2012)
20	Caspase-8 Homo sapiens	3.4.22.61	NSC321206	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 1.03, β = 0.19, K_X = 0.40 μM	Feldman (2012)
21	Caspase-8 Homo sapiens	3.4.22.61	NSC310547	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 1.07, β = 0.32, K_X = 0.67 μM	Feldman (2012)
22	Glycogen phosphorylase Neurospora crassa	2.4.1.1	Glucose-6-phosphate	Glucose-1-phosphate (synthesis direction)	Partial noncompetitive inhibition α = 1, β = 0.47, K_X = 2.1 mM	Gold (1974)
23	Glycogen phosphorylase Neurospora crassa	2.4.1.1	Glucose-6-phosphate	Glycogen (synthesis direction)	Partial noncompetitive inhibition α = 1, β = 0.42, K_X = 1.6 mM	Gold (1974)
24	Glycogen phosphorylase Neurospora crassa	2.4.1.1	Glucose-6-phosphate	Phosphate (phosphorolysis direction)	Partial noncompetitive inhibition ⁽¹⁰⁾ β = 0.42-0.52, K_X = 1.6-4.0 mM	Gold (1974)
25	Glycogen phosphorylase Neurospora crassa	2.4.1.1	Glucose-6-phosphate	Glycogen (phosphorolysis direction)	Partial noncompetitive inhibition ⁽¹⁰⁾ β = 0.42-0.52, K_X = 1.6-4.0 mM	Gold (1974)
26	Peroxiredoxin Homo sapiens	1.11.1.15	4-Methylcatechol	H₂O₂	Partial mixed noncompetitive inhibition α = 1.09, β = 0.34, K_X = 0.33 mM	Chow (2016)
27	Sucrose α-glucosidase ⁽¹¹⁾ Mus musculus (Balb c)	3.2.1.48	Na⁺ (pH = 8.5)	Sucrose	Noncompetitive inhibition α = 1, β = 0.68, K_X not calculated	Gupta (2009)
28	Caspase-7 Homo sapiens	3.4.22.60	NSC321206	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 0.84, β = 0.15, K_X = 0.31 μM	Feldman (2012)
29	Caspase-2 Homo sapiens	3.4.22.55	NSC321205	(Z-DEVD)2Rh110 ⁽⁹⁾	Partial noncompetitive inhibition α = 0.96, β = 0.16, K_X = 0.69 μM	Feldman (2012)
30	Leukocyte elastase Homo sapiens	3.4.21.37	FURA-2	MeO-Suc-Ala-Ala-Pro-Val-p-nitroanilide	Partial noncompetitive inhibition α = 1.0, β = 0.12, K_X = 0.68 mM	Tyagi (1991)
31	Receptor protein-tyrosine kinase Homo sapiens	2.7.10.1	RG 14467	Peptide K1 ⁽¹²⁾	Hyperbolic noncompetitive inhibition α ≈ 1, β ≈ 0.25, K_X ≤ 30 nM	Hsu (1991)

⁽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 K_X, 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, K_X 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⁾ RG1503, average Mr = 47,000. The stoichiometry of binding was enzyme:inhibitor = 6:1. Tightly bound modifier.

⁽⁵⁾ RG1192, average Mr = 140,000, The stoichiometry of binding was enzyme:inhibitor = 20:1. Tightly bound modifier.

⁽⁶⁾ Flavone = 2-phenyl-4H-1-benzopyran-4-one.

⁽⁷⁾ DCPIP = 2,6-dichorophenolindophenol (replaces a natural quinone for in vitro studies)

⁽⁸⁾ Product inhibition. Hyperbolic inhibition clearly demonstrated (α = 1, β < 1 ) but the value o. β was not shown.

⁽⁹⁾ (Z-DEVD)2Rh110 = (Cbz-Asp-Glu-Val-Asp)2 Rhodamine 110.

⁽¹⁰⁾ In the phosphorolysis direction the inhibition is reported to be partial noncompetitive with respect to both phosphate and glycogen and only a global range is given for the parameters: β = 0.42-0.52, K_X= 1.6-4.0 mM.

⁽¹¹⁾ The mechanism is species- and pH-dependent. See also under HSpA and HMx(Sp=Ca)A.

⁽¹²⁾ K1 is a peptide containing the major autophosphorylation site (Tyr-1173) of the epidermal growth factor receptor. Tight-binding (quasi irreversible) slow-onset inhibition; K_X estimated by the authors. Approximate values of α and β were estimated from the data in Fig. 11.

References

Baici A, Salgam P, Fehr K, Böni A (1981) Inhibition of human elastase from polymorphonuclear leucocytes by gold sodium thiomalate and pentosan polysulfate (SP-54). Biochem Pharmacol 30: 703-708. doi:10.1016/0006-2952(81)90154-4
Berman HA, Leonard K (1990) Ligand exclusion on acetylcholinesterase. Biochemistry 29: 10640-10649. doi:10.1021/bi00499a010
Chow ML, Troussicot L, Martin M, Doumèche B, Guillière F, Lancelin J-M (2016) Predicting and understanding the enzymatic inhibition of human peroxiredoxin 5 by 4-substituted pyrocatechols by combining funnel metadynamics, solution NMR, and steady-state kinetics. Biochemistry 55: 3469-3480. doi:10.1021/acs.biochem.6b00367
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
Feldman T, Kabaleeswaran V, Jang SB, Antczak C, Djaballah H, Wu H, Jiang X (2012) A class of allosteric caspase inhibitors identified by high-throughput screening. Mol Cell 47: 585-595. doi:10.1016/j.molcel.2012.06.007
Gold MH, Farrand RJ, Livoni JP, Segel IH (1974) Neurospora crassa glycogen phosphorylase: Interconversion and kinetic properties of the “active” form. Arch Biochem Biophys 161: 515-527. doi:10.1016/0003-9861(74)90334-8
Gupta S, Mahmood S, Mahmood A (2009) Kinetic characteristics of brush border sucrase activation by Na+ ions in mice intestine. Indian J Exp Biol 47: 811-815.
Hsu CY, Persons PE, Spada AP, Bednar RA, Levitzki A, Zilberstein A (1991) Kinetic analysis of the inhibition of the epidermal growth factor receptor tyrosine kinase by lavendustin-A and its analogue. J Biol Chem 266: 21105-21112
Ledoux D, Papy-Garcia D, Escartin Q, Sagot MA, Cao Y, Barritault D, Courtois J, Hornebeck W, Caruelle JP (2000) Human plasmin enzymatic activity is inhibited by chemically modified dextrans. J Biol Chem 275: 29383-29390. doi:10.1074/jbc.M000837200
O’Farrell F, Loog M, Janson IM, Ek P (1999) Kinetic study of the inhibition of CK2 by heparin fragments of different length. Biochim Biophys Acta 1433: 68-75. doi:10.1016/S0167-4838(99)00147-8
Raina A, Hyvönen T, Eloranta T, Voutilainen M, Samejima K, Yamanoha B (1984) Polyamine synthesis in mammalian tissues. Isolation and characterization of spermidine synthase from bovine brain. Biochem J 219: 991-1000. doi:10.1042/bj2190991
Tyagi SC, Simon SR (1991) Interaction of neutrophil elastase with hydrophobic polyanionic chelators. Biochem Cell Biol 69: 624-629. doi:10.1139/o91-092
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