Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria

Uroporphyrinogen decarboxylase is an essential enzyme in all organisms and functions in the heme biosynthetic pathway, catalyzing the decarboxylation of the four acetate groups of uroporphyrinogen to form coproporphyrinogen. This work examines whether the four sequential decarboxylations occur at th...

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Autores principales:	Chaufan, Rosa Gabriela, Corvi, María Martha, San Martín de Viale, Leonor Carmen, Ríos de Molina, María del Carmen
Publicado:	2005
Materias:	Active Site Competition Plot Heme Biosynthesis Hexachlorobenzene Pentacarboxyporphyrinogen Porphyria Cutanea Tarda (PCT) Tetrapyr-role UROD Uroporphyrinogen Decarboxylase acetic acid coproporphyrinogen hexachlorobenzene pentacarboxyporphyrinogen porphyrinogen unclassified drug uroporphyrinogen uroporphyrinogen decarboxylase animal model article chemical reaction decarboxylation enzyme active site enzyme activity enzyme kinetics enzyme mechanism enzyme purification enzyme structure nonhuman porphyria rat Animals Female Kinetics Liver Porphyrias Porphyrinogens Rats Rats, Wistar Uroporphyrinogens
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10956670_v19_n1_p19_Chaufan http://hdl.handle.net/20.500.12110/paper_10956670_v19_n1_p19_Chaufan
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

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spelling	paper:paper_10956670_v19_n1_p19_Chaufan2023-06-08T16:07:02Z Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria Chaufan, Rosa Gabriela Corvi, María Martha San Martín de Viale, Leonor Carmen Ríos de Molina, María del Carmen Active Site Competition Plot Heme Biosynthesis Hexachlorobenzene Pentacarboxyporphyrinogen Porphyria Cutanea Tarda (PCT) Tetrapyr-role UROD Uroporphyrinogen Decarboxylase acetic acid coproporphyrinogen hexachlorobenzene pentacarboxyporphyrinogen porphyrinogen unclassified drug uroporphyrinogen uroporphyrinogen decarboxylase animal model article chemical reaction decarboxylation enzyme active site enzyme activity enzyme kinetics enzyme mechanism enzyme purification enzyme structure nonhuman porphyria rat Animals Female Hexachlorobenzene Kinetics Liver Porphyrias Porphyrinogens Rats Rats, Wistar Uroporphyrinogen Decarboxylase Uroporphyrinogens Uroporphyrinogen decarboxylase is an essential enzyme in all organisms and functions in the heme biosynthetic pathway, catalyzing the decarboxylation of the four acetate groups of uroporphyrinogen to form coproporphyrinogen. This work examines whether the four sequential decarboxylations occur at the same active site, and explores whether hexachlorobenzene-induced porphyria affects the behavior of the enzyme. For this purpose, kinetic competition studies were done with mixtures of uroporphyrinogen III and pentacarboxyporphyrinogen III. With the enzyme from normal rats, a constant velocity was obtained with all the mixtures, indicating that uroporphyrinogen and pentacarboxy-porphyrinogen react at the same active site, i.e. the first and fourth decarboxylations occur at the same site. In contrast, in experiments with enzyme from rats with hexachlorobenzene-induced porphyria, the total rate for mixtures was always lower than the reference rate; and a curve with a deep minimum was obtained, indicating that the two reactions occur at functionally different sites, but with cross-inhibition. This suggests that the modifications induced in the enzyme by hexachlorobenzene cause the two active sites to become nonequivalent and functionally different. The question is discussed how the hexachlorobenzene treatment may produce this abnormal kinetic behavior, and alternative hypotheses are considered. © 2005 Wiley Periodicals, Inc. Fil:Chaufan, G. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Corvi, M.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:San Martín De Viale, L.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Ríos De Molina, M.D.C. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 2005 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10956670_v19_n1_p19_Chaufan http://hdl.handle.net/20.500.12110/paper_10956670_v19_n1_p19_Chaufan
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	Active Site Competition Plot Heme Biosynthesis Hexachlorobenzene Pentacarboxyporphyrinogen Porphyria Cutanea Tarda (PCT) Tetrapyr-role UROD Uroporphyrinogen Decarboxylase acetic acid coproporphyrinogen hexachlorobenzene pentacarboxyporphyrinogen porphyrinogen unclassified drug uroporphyrinogen uroporphyrinogen decarboxylase animal model article chemical reaction decarboxylation enzyme active site enzyme activity enzyme kinetics enzyme mechanism enzyme purification enzyme structure nonhuman porphyria rat Animals Female Hexachlorobenzene Kinetics Liver Porphyrias Porphyrinogens Rats Rats, Wistar Uroporphyrinogen Decarboxylase Uroporphyrinogens
spellingShingle	Active Site Competition Plot Heme Biosynthesis Hexachlorobenzene Pentacarboxyporphyrinogen Porphyria Cutanea Tarda (PCT) Tetrapyr-role UROD Uroporphyrinogen Decarboxylase acetic acid coproporphyrinogen hexachlorobenzene pentacarboxyporphyrinogen porphyrinogen unclassified drug uroporphyrinogen uroporphyrinogen decarboxylase animal model article chemical reaction decarboxylation enzyme active site enzyme activity enzyme kinetics enzyme mechanism enzyme purification enzyme structure nonhuman porphyria rat Animals Female Hexachlorobenzene Kinetics Liver Porphyrias Porphyrinogens Rats Rats, Wistar Uroporphyrinogen Decarboxylase Uroporphyrinogens Chaufan, Rosa Gabriela Corvi, María Martha San Martín de Viale, Leonor Carmen Ríos de Molina, María del Carmen Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
topic_facet	Active Site Competition Plot Heme Biosynthesis Hexachlorobenzene Pentacarboxyporphyrinogen Porphyria Cutanea Tarda (PCT) Tetrapyr-role UROD Uroporphyrinogen Decarboxylase acetic acid coproporphyrinogen hexachlorobenzene pentacarboxyporphyrinogen porphyrinogen unclassified drug uroporphyrinogen uroporphyrinogen decarboxylase animal model article chemical reaction decarboxylation enzyme active site enzyme activity enzyme kinetics enzyme mechanism enzyme purification enzyme structure nonhuman porphyria rat Animals Female Hexachlorobenzene Kinetics Liver Porphyrias Porphyrinogens Rats Rats, Wistar Uroporphyrinogen Decarboxylase Uroporphyrinogens
description	Uroporphyrinogen decarboxylase is an essential enzyme in all organisms and functions in the heme biosynthetic pathway, catalyzing the decarboxylation of the four acetate groups of uroporphyrinogen to form coproporphyrinogen. This work examines whether the four sequential decarboxylations occur at the same active site, and explores whether hexachlorobenzene-induced porphyria affects the behavior of the enzyme. For this purpose, kinetic competition studies were done with mixtures of uroporphyrinogen III and pentacarboxyporphyrinogen III. With the enzyme from normal rats, a constant velocity was obtained with all the mixtures, indicating that uroporphyrinogen and pentacarboxy-porphyrinogen react at the same active site, i.e. the first and fourth decarboxylations occur at the same site. In contrast, in experiments with enzyme from rats with hexachlorobenzene-induced porphyria, the total rate for mixtures was always lower than the reference rate; and a curve with a deep minimum was obtained, indicating that the two reactions occur at functionally different sites, but with cross-inhibition. This suggests that the modifications induced in the enzyme by hexachlorobenzene cause the two active sites to become nonequivalent and functionally different. The question is discussed how the hexachlorobenzene treatment may produce this abnormal kinetic behavior, and alternative hypotheses are considered. © 2005 Wiley Periodicals, Inc.
author	Chaufan, Rosa Gabriela Corvi, María Martha San Martín de Viale, Leonor Carmen Ríos de Molina, María del Carmen
author_facet	Chaufan, Rosa Gabriela Corvi, María Martha San Martín de Viale, Leonor Carmen Ríos de Molina, María del Carmen
author_sort	Chaufan, Rosa Gabriela
title	Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
title_short	Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
title_full	Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
title_fullStr	Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
title_full_unstemmed	Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
title_sort	abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria
publishDate	2005
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_10956670_v19_n1_p19_Chaufan http://hdl.handle.net/20.500.12110/paper_10956670_v19_n1_p19_Chaufan
work_keys_str_mv	AT chaufanrosagabriela abnormalkineticbehaviorofuroporphyrinogendecarboxylaseobtainedfromratswithhexachlorobenzeneinducedporphyria AT corvimariamartha abnormalkineticbehaviorofuroporphyrinogendecarboxylaseobtainedfromratswithhexachlorobenzeneinducedporphyria AT sanmartindevialeleonorcarmen abnormalkineticbehaviorofuroporphyrinogendecarboxylaseobtainedfromratswithhexachlorobenzeneinducedporphyria AT riosdemolinamariadelcarmen abnormalkineticbehaviorofuroporphyrinogendecarboxylaseobtainedfromratswithhexachlorobenzeneinducedporphyria
_version_	1768546080738246656

Abnormal kinetic behavior of uroporphyrinogen decarboxylase obtained from rats with hexachlorobenzene-induced porphyria

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