Cardiotoxin of the Indian cobra (Naja naja) is a pyrophosphatase.

ABSTRACT

An inorganic pyrophosphatase has been purified to apparent homogeniety from Indian cobra (Naja naja) venom, with a ten fold increase in specific activity. The enzyme activity is intrinsic to a protein fraction in the venom which is normally termed cardiotoxin, cobramine, cytotoxin and so on. The enzyme shows a low Km (70 μΜ) and high heat stability. The enzyme was active against sodium pyrophosphate; it also hydrolyses a few mononucletides and sugar phosphates at much lower rates. The physiological significance of inorganic pyro phosphatase in venom is discussed.