A rapid histidine decarboxylase assay

✍ Scribed by Robert Roskoski Jr; Laura M. Roskoski

• Publisher: Elsevier Science
• Year: 1978
• Tongue: English
• Weight: 307 KB
• Volume: 87
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(78)90599-7

✦ Synopsis

A Rapid Histidine Decarboxylase Assay1

Histidine decarboxylase (EC 4.1.1.22) catalyzes the conversion of histidine to histamine. Because current assays for enzyme activity are time consuming and require additional enzymes or large amounts of tissue, a rapid radioisotopic assay was devised. Using commercially available radioactive histidine (without additional purification), the enzyme mediates the formation of histamine. The product is resolved from precursor by paper electrophoresis in a formic acid-acetic acid solution for 15 min. After drying and ninhydrin staining, radioactive histamine is measured by liquid scintillation spectrometry. This assay procedure is sensitive enough to measure decarboxylase activity in milligram quantities of rat brain.