Abstract
The mammalian enzyme pantetheinase, which hydrolyzes pantetheine to pantothenic acid and cysteamine, is inhibited by many thiol reagents and activated by thiols. Two thiol groups of different reactivity and accessibility are involved in the catalytic process [Ricci, G., Nardini, M., Chiaraluce, R., Dupre, S. and Cavallini, D. (1986) Biochim. Biophys. Acta 870, 82-91]. The inhibition kinetics by some natural and synthetic disulfides [pantethine, cystamine, 5,5'-dithiobis(2-nitrobenzoic acid), 4,4'-dithiodipyridine and oxidized mercaptoethanol] has been studied by two experimental approaches, either by monitoring activity after incubation of the enzyme with the inhibitor or by determining the progress curves in the presence of substrate and inhibitor. Data reported here indicate that pantetheinase reacts irreversibly with various disulfides in a time-dependent manner with the formation of a mixed disulfide apparently preceeded by a conformational change, giving a modified E* form with new kinetic parameters. This modified form may be further competitively inhibited by disulfides interacting with the enzyme at the active site.
| Original language | English |
|---|---|
| Pages (from-to) | 81-86 |
| Number of pages | 6 |
| Journal | European Journal of Biochemistry |
| Volume | 226 |
| Issue number | 1 |
| DOIs | |
| Publication status | Published - 1994 |
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- Biochemistry
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A kinetic study on pantetheinase inhibition by disulfides. / Pitari, G.; Maurizi, G.; Ascenzi, P.; Ricci, G.; Dupre, S.
In: European Journal of Biochemistry, Vol. 226, No. 1, 1994, p. 81-86.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - A kinetic study on pantetheinase inhibition by disulfides
AU - Pitari, G.
AU - Maurizi, G.
AU - Ascenzi, P.
AU - Ricci, G.
AU - Dupre, S.
PY - 1994
Y1 - 1994
N2 - The mammalian enzyme pantetheinase, which hydrolyzes pantetheine to pantothenic acid and cysteamine, is inhibited by many thiol reagents and activated by thiols. Two thiol groups of different reactivity and accessibility are involved in the catalytic process [Ricci, G., Nardini, M., Chiaraluce, R., Dupre, S. and Cavallini, D. (1986) Biochim. Biophys. Acta 870, 82-91]. The inhibition kinetics by some natural and synthetic disulfides [pantethine, cystamine, 5,5'-dithiobis(2-nitrobenzoic acid), 4,4'-dithiodipyridine and oxidized mercaptoethanol] has been studied by two experimental approaches, either by monitoring activity after incubation of the enzyme with the inhibitor or by determining the progress curves in the presence of substrate and inhibitor. Data reported here indicate that pantetheinase reacts irreversibly with various disulfides in a time-dependent manner with the formation of a mixed disulfide apparently preceeded by a conformational change, giving a modified E* form with new kinetic parameters. This modified form may be further competitively inhibited by disulfides interacting with the enzyme at the active site.
AB - The mammalian enzyme pantetheinase, which hydrolyzes pantetheine to pantothenic acid and cysteamine, is inhibited by many thiol reagents and activated by thiols. Two thiol groups of different reactivity and accessibility are involved in the catalytic process [Ricci, G., Nardini, M., Chiaraluce, R., Dupre, S. and Cavallini, D. (1986) Biochim. Biophys. Acta 870, 82-91]. The inhibition kinetics by some natural and synthetic disulfides [pantethine, cystamine, 5,5'-dithiobis(2-nitrobenzoic acid), 4,4'-dithiodipyridine and oxidized mercaptoethanol] has been studied by two experimental approaches, either by monitoring activity after incubation of the enzyme with the inhibitor or by determining the progress curves in the presence of substrate and inhibitor. Data reported here indicate that pantetheinase reacts irreversibly with various disulfides in a time-dependent manner with the formation of a mixed disulfide apparently preceeded by a conformational change, giving a modified E* form with new kinetic parameters. This modified form may be further competitively inhibited by disulfides interacting with the enzyme at the active site.
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UR - http://www.scopus.com/inward/citedby.url?scp=0028116761&partnerID=8YFLogxK
U2 - 10.1111/j.1432-1033.1994.tb20028.x
DO - 10.1111/j.1432-1033.1994.tb20028.x
M3 - Article
VL - 226
SP - 81
EP - 86
JO - European Journal of Biochemistry
JF - European Journal of Biochemistry
SN - 0014-2956
IS - 1
ER -