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Nitric oxide synthase activity from a hematophagous insect salivary gland
Author(s) -
Ribeiro José M.C.,
Nussenzveig Roberta H.
Publication year - 1993
Publication title -
febs letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.593
H-Index - 257
eISSN - 1873-3468
pISSN - 0014-5793
DOI - 10.1016/0014-5793(93)80265-v
Subject(s) - rhodnius prolixus , tetrahydrobiopterin , insect , nitric oxide synthase , citrulline , biochemistry , nitric oxide , biology , blood meal , vertebrate , salivary gland , calmodulin , arginine , malpighian tubule system , atp synthase , chemistry , enzyme , endocrinology , zoology , botany , amino acid , midgut , gene , larva
The salivary glands of the hematophagous insect, Rhodnius prolixus , contain a nitrosylhemeprotein that dissociates its ligand, NO, to the host tissues while the insect is searching for a blood meal. We now report a salivary nitric oxide synthase activity in this insect. The activity is dependent on NADPH, FAD, tetrahydrobiopterin, calmodulin, Ca 2+ , and converts arginine to citrulline while producing vasorelaxing activity. Molecular sieving indicates a molecular weight of 185 kDa, coeluting with a diaphorase activity. Results indicate similarity of this insect activity to the vertebrate constitutive NO synthase, suggesting NO synthesis is an evolutionary old biological pathway.