Metal and Nonprotein Constituents in Snake Venoms

Abstract

Snake venoms have been extensively studied in the past and, in general, their gross composition has been quite well-established. Approximately 90% of the dry weight of most venoms consists of protein material. Most of the toxic and biologically active components of the venom are proteins from this major fraction of the dry weight. The nonprotein portion of the venom is a much smaller amount of material and, in general, is biologically less active. Included in the nonprotein fraction are metal ions, inorganic anions, and some small organic molecules including peptides, lipids, nucleosides, carbohydrates, and amines. Devi (1968) in a review entitled ``The protein and nonprotein constituents of snake venoms'' has covered the literature pertaining to nonprotein constituents up to that time reasonably well. The review also contains substantial amounts of data from the laboratory of Devi that does not appear to be published in the primary literature. In this review, I shall limit citations primarily to those that have appeared since the review by Devi (1968) except where older literature citations are important for direct comparison or are very pertinent for discussion purposes.