Interaction with substrate sensitises caspase-3 to inactivation by hydrogen peroxide

Mark B. Hampton; Ivan Stamenkovic; Christine C. Winterbourn

doi:10.1016/S0014-5793(02)02629-7

Interaction with substrate sensitises caspase-3 to inactivation by hydrogen peroxide

Mark B. Hampton, Ivan Stamenkovic, Christine C. Winterbourn

Research output: Contribution to journal › Article › peer-review

62 Scopus citations

Abstract

Caspases have an active site cysteine whose oxidation blocks catalytic activity. Caspase activity, measured in lysates of apoptotic cells, was inhibited by H₂O₂ with an IC₅₀ of 7 μM. Recombinant caspase-3 was directly inhibited by H₂O₂, with an estimated second-order rate constant of 750 M^-1 s^-1. These values were determined when H₂O₂ was added while the caspases were cleaving a peptide substrate. There was a 40-fold decrease in sensitivity to inactivation if the substrate was absent at the time of H₂O₂ addition. These results rationalise conflicting reports of the sensitivity of caspase-3 to H₂O₂, and identify a novel mechanism for sensitising a thiol enzyme to oxidative inactivation.

Original language	English
Pages (from-to)	229-232
Number of pages	4
Journal	FEBS Letters
Volume	517
Issue number	1-3
DOIs	https://doi.org/10.1016/S0014-5793(02)02629-7
State	Published - 24 Apr 2002
Externally published	Yes

Keywords

Apoptosis
Caspase
Cysteine
Hydrogen peroxide
Oxidation
Thiol

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10.1016/S0014-5793(02)02629-7

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title = "Interaction with substrate sensitises caspase-3 to inactivation by hydrogen peroxide",

abstract = "Caspases have an active site cysteine whose oxidation blocks catalytic activity. Caspase activity, measured in lysates of apoptotic cells, was inhibited by H2O2 with an IC50 of 7 μM. Recombinant caspase-3 was directly inhibited by H2O2, with an estimated second-order rate constant of 750 M-1 s-1. These values were determined when H2O2 was added while the caspases were cleaving a peptide substrate. There was a 40-fold decrease in sensitivity to inactivation if the substrate was absent at the time of H2O2 addition. These results rationalise conflicting reports of the sensitivity of caspase-3 to H2O2, and identify a novel mechanism for sensitising a thiol enzyme to oxidative inactivation.",

keywords = "Apoptosis, Caspase, Cysteine, Hydrogen peroxide, Oxidation, Thiol",

author = "Hampton, {Mark B.} and Ivan Stamenkovic and Winterbourn, {Christine C.}",

note = "Funding Information: This work was supported by a Marsden Grant from the Royal Society of New Zealand to M.B.H. and C.C.W., and NIH Grants GM54176 and GM48614 to I.S. We thank Dr. Don Nicholson for the gift of recombinant caspase-3.",

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doi = "10.1016/S0014-5793(02)02629-7",

language = "English",

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T1 - Interaction with substrate sensitises caspase-3 to inactivation by hydrogen peroxide

AU - Hampton, Mark B.

AU - Stamenkovic, Ivan

AU - Winterbourn, Christine C.

N1 - Funding Information: This work was supported by a Marsden Grant from the Royal Society of New Zealand to M.B.H. and C.C.W., and NIH Grants GM54176 and GM48614 to I.S. We thank Dr. Don Nicholson for the gift of recombinant caspase-3.

PY - 2002/4/24

Y1 - 2002/4/24

N2 - Caspases have an active site cysteine whose oxidation blocks catalytic activity. Caspase activity, measured in lysates of apoptotic cells, was inhibited by H2O2 with an IC50 of 7 μM. Recombinant caspase-3 was directly inhibited by H2O2, with an estimated second-order rate constant of 750 M-1 s-1. These values were determined when H2O2 was added while the caspases were cleaving a peptide substrate. There was a 40-fold decrease in sensitivity to inactivation if the substrate was absent at the time of H2O2 addition. These results rationalise conflicting reports of the sensitivity of caspase-3 to H2O2, and identify a novel mechanism for sensitising a thiol enzyme to oxidative inactivation.

AB - Caspases have an active site cysteine whose oxidation blocks catalytic activity. Caspase activity, measured in lysates of apoptotic cells, was inhibited by H2O2 with an IC50 of 7 μM. Recombinant caspase-3 was directly inhibited by H2O2, with an estimated second-order rate constant of 750 M-1 s-1. These values were determined when H2O2 was added while the caspases were cleaving a peptide substrate. There was a 40-fold decrease in sensitivity to inactivation if the substrate was absent at the time of H2O2 addition. These results rationalise conflicting reports of the sensitivity of caspase-3 to H2O2, and identify a novel mechanism for sensitising a thiol enzyme to oxidative inactivation.

KW - Apoptosis

KW - Caspase

KW - Cysteine

KW - Hydrogen peroxide

KW - Oxidation

KW - Thiol

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U2 - 10.1016/S0014-5793(02)02629-7

DO - 10.1016/S0014-5793(02)02629-7

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AN - SCOPUS:0037165630

SN - 0014-5793

VL - 517

SP - 229

EP - 232

JO - FEBS Letters

JF - FEBS Letters

IS - 1-3

ER -

Interaction with substrate sensitises caspase-3 to inactivation by hydrogen peroxide

Abstract

Keywords

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