J. M. Palacios, G. Mengod, F. Picatoste, M. Grau, I. Blanco

Research output: Contribution to journalArticleResearchpeer-review

14 Citations (Scopus)


Abstract– The properties of histidine decarboxylase (l‐histidine carboxylyase EC 4.1,1.22) have been studied in a whole rat brain homogenate. Optimum pH depended upon substrate concentration; the variations of Km and Vmax were determined as a function of pH. pH values lower than 6.0 caused a loss of enzymic activity; activity was stable at pH values higher than 6.0. Enzyme activity was proportional to temperature in the range 30‐45°C; temperature characteristic (μ) and Q10 were determined and thermal inactivation was studied. Addition of pyridoxal 5′‐phosphate increased enzyme activity. Dialysis of homogenates against phosphate buffer caused a partial loss of enzyme activity which could be restored by addition of the coenzyme to the incubation mixture. Enzyme activity was inhibited by α‐methylhistidine and benzene and was unaffected by α‐methyl DOPA. The properties correspond to those of a ‘specific’ histidine decarboxylase. However, the brain enzyme differs from the corresponding enzyme in peripheral tissues in the inability to achieve a total inhibition of activity by dialysis. Copyright © 1976, Wiley Blackwell. All rights reserved
Original languageEnglish
Pages (from-to)1455-1460
JournalJournal of Neurochemistry
Publication statusPublished - 1 Jan 1976


Dive into the research topics of 'PROPERTIES OF RAT BRAIN HISTIDINE DECARBOXYLASE'. Together they form a unique fingerprint.

Cite this