Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?

Rhodanese from normal individuals' and acute intermittent porphyria (AIP) patients' red blood cells (RBC) was purified 134-fold, with a final yield of 20%. Normal and AIP RBC rhodanese exhibited practically the same chromatographic behaviour and also an optimum pH around 9.3. Kinetic studi...

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Autores principales:	Vázquez, Elba Susana, Buzaleh, Ana María, Batlle, Alcira María del Carmen
Publicado:	1986
Materias:	5 aminolevulinate synthase cystine thiocyanic acid thiosulfate thiosulfate sulfurtransferase unclassified drug blood and hemopoietic system chromatography cytochemistry cytology drug efficacy erythrocyte human human cell porphyria priority journal
Acceso en línea:	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03056651_v14_n10_p999_Vazquez http://hdl.handle.net/20.500.12110/paper_03056651_v14_n10_p999_Vazquez
Aporte de:	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) de Universidad de Buenos Aires

id	paper:paper_03056651_v14_n10_p999_Vazquez
record_format	dspace
spelling	paper:paper_03056651_v14_n10_p999_Vazquez2023-06-08T15:30:48Z Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias? Vázquez, Elba Susana Buzaleh, Ana María Batlle, Alcira María del Carmen 5 aminolevulinate synthase cystine thiocyanic acid thiosulfate thiosulfate sulfurtransferase unclassified drug blood and hemopoietic system chromatography cytochemistry cytology drug efficacy erythrocyte human human cell porphyria priority journal Rhodanese from normal individuals' and acute intermittent porphyria (AIP) patients' red blood cells (RBC) was purified 134-fold, with a final yield of 20%. Normal and AIP RBC rhodanese exhibited practically the same chromatographic behaviour and also an optimum pH around 9.3. Kinetic studies from normal RBC rhodanese showed substrate inhibition at high thiosulphate and cyanide concentration, while results obtained for the AIP RBC rhodanese showed substrate inhibition at high cyanide concentrations, but no inhibition at high thiosulphate concentration. Vmax and Km were similar for normal and AIP rhodanese when cyanide was the variable substrate, but those parameters differed when thiosulphate varied. On the basis of these findings it is postulated that in AIP, as a consequence of reduced affinity of rhodanese for thiosulphate, cystine trisulphide, the ALA-S activator and sulphur donor substrate for rhodanese, would not be acted on or degraded, remaining in higher concentrations than normal. As a result the activity of ALA-S would be increased, failing to operate the rhodanese control mechanism. Fil:Vazquez, E. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Buzaleh, A.M. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. Fil:Batlle, A. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; Argentina. 1986 https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03056651_v14_n10_p999_Vazquez http://hdl.handle.net/20.500.12110/paper_03056651_v14_n10_p999_Vazquez
institution	Universidad de Buenos Aires
institution_str	I-28
repository_str	R-134
collection	Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA)
topic	5 aminolevulinate synthase cystine thiocyanic acid thiosulfate thiosulfate sulfurtransferase unclassified drug blood and hemopoietic system chromatography cytochemistry cytology drug efficacy erythrocyte human human cell porphyria priority journal
spellingShingle	5 aminolevulinate synthase cystine thiocyanic acid thiosulfate thiosulfate sulfurtransferase unclassified drug blood and hemopoietic system chromatography cytochemistry cytology drug efficacy erythrocyte human human cell porphyria priority journal Vázquez, Elba Susana Buzaleh, Ana María Batlle, Alcira María del Carmen Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
topic_facet	5 aminolevulinate synthase cystine thiocyanic acid thiosulfate thiosulfate sulfurtransferase unclassified drug blood and hemopoietic system chromatography cytochemistry cytology drug efficacy erythrocyte human human cell porphyria priority journal
description	Rhodanese from normal individuals' and acute intermittent porphyria (AIP) patients' red blood cells (RBC) was purified 134-fold, with a final yield of 20%. Normal and AIP RBC rhodanese exhibited practically the same chromatographic behaviour and also an optimum pH around 9.3. Kinetic studies from normal RBC rhodanese showed substrate inhibition at high thiosulphate and cyanide concentration, while results obtained for the AIP RBC rhodanese showed substrate inhibition at high cyanide concentrations, but no inhibition at high thiosulphate concentration. Vmax and Km were similar for normal and AIP rhodanese when cyanide was the variable substrate, but those parameters differed when thiosulphate varied. On the basis of these findings it is postulated that in AIP, as a consequence of reduced affinity of rhodanese for thiosulphate, cystine trisulphide, the ALA-S activator and sulphur donor substrate for rhodanese, would not be acted on or degraded, remaining in higher concentrations than normal. As a result the activity of ALA-S would be increased, failing to operate the rhodanese control mechanism.
author	Vázquez, Elba Susana Buzaleh, Ana María Batlle, Alcira María del Carmen
author_facet	Vázquez, Elba Susana Buzaleh, Ana María Batlle, Alcira María del Carmen
author_sort	Vázquez, Elba Susana
title	Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
title_short	Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
title_full	Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
title_fullStr	Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
title_full_unstemmed	Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
title_sort	reduced thiosulphate affinity for erythrocyte rhodanese: an explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?
publishDate	1986
url	https://bibliotecadigital.exactas.uba.ar/collection/paper/document/paper_03056651_v14_n10_p999_Vazquez http://hdl.handle.net/20.500.12110/paper_03056651_v14_n10_p999_Vazquez
work_keys_str_mv	AT vazquezelbasusana reducedthiosulphateaffinityforerythrocyterhodaneseanexplanationforincreaseddaminolevulinicsynthetaseactivityinsomeporphyrias AT buzalehanamaria reducedthiosulphateaffinityforerythrocyterhodaneseanexplanationforincreaseddaminolevulinicsynthetaseactivityinsomeporphyrias AT batllealciramariadelcarmen reducedthiosulphateaffinityforerythrocyterhodaneseanexplanationforincreaseddaminolevulinicsynthetaseactivityinsomeporphyrias
_version_	1768543609537167360

Reduced thiosulphate affinity for erythrocyte rhodanese: An explanation for increased δ-aminolevulinic synthetase activity in some porphyrias?

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