New fluorogenic substrates for renin

✍ Scribed by Kazuo Murakami; Tamiko Ohsawa; Shigehisa Hirose; Katsumi Takada; Shumpei Sakakibara

• Publisher: Elsevier Science
• Year: 1981
• Tongue: English
• Weight: 610 KB
• Volume: 110
• Category: Article
• ISSN: 0003-2697
• DOI: 10.1016/0003-2697(81)90140-8

✦ Synopsis

A simple and sensitive fluorometric assay was developed to test renin activity within several hours. Two new fluorogenic peptides, Arg-Pro-Phe-His-Leu-Leu-Val-Tyr-4-methylcoumaryl-7-amide (octapeptide-MCA) and a succinyl derivative of the octapeptide-MCA were synthesized and used as a renin substrate. Renin cleaved the substrates at the Leu-Leu bond, releasing Leu-Val-Tyr-MCA.

Three ammo acids of this product were then successively split off by the auxiliary enzyme, leucine aminopeptidase, to liberate free 7-amino-4-methylcoumarin (AMC). The generation of the fluorescent 7-amino-4-methylcoumarin was proportional to renin concentrations up to 100 mGoldblatt U/tube. The optimal pH of renin reaction for both substrates was 6.5 to 7.0. As low as 5 mGoldblatt U of renin could be detected by this method. This method was applied to the assay of renin during its purification.