CLONING AND SEQUENCE-ANALYSIS OF A BOTHROPS-JARARACA CDNA-ENCODING A PRECURSOR OF 7 BRADYKININ-POTENTIATING PEPTIDES AND A C-TYPE NATRIURETIC PEPTIDE

A 1.8-kb cDNA clone was isolated from a Bothrops jararaca venom gland cDNA library that encodes a 256-aa precursor for bradykinin-potentiati ng peptides (angiotensin-converting enzyme inhibitors) and a C-type na triuretic peptide (CNP), The seven bradykinin-potentiating peptides ar e aligned tandemly after the hydrophobic signal peptide sequence, foll owed by a putative intervening sequence and a CNP at the C terminus. N orthern blot analysis indicated the predominant expression of a 1.8-kb mRNA in the venom glands as well as in the spleen and the brain. Two lower intensity mRNA bands of 3.5 kb and 5.7 kb also hybridized to the cDNA clone. Radioimmunoassay for the CNP was performed using the anti serum against rat CNP, The presence of CNP immunoreactivity was detect ed in the low molecular weight fraction of the Bothrops jararaca venom .