La molecula DRACULIN es el factor anticoagulante que esta presente en la saliva del vampiro. Estructuralmente es una gran glicoproteina formada por una secuencia de 411 aminoacidos.
A nivel fisiologico, actua como un anticoagulante, inhibiendo el factor de coagulacion IX (IXa) y X (Xa), manteniendo el flujo continuo de sangre, mientras, el murcielago bebe la sangre de su victima como parte de su dieta.
Este anticoagulante es 100 veces mas potente que cualquier otro conocido y es prescrito en medicina para pacientes con ataques cardiacos y trombosis.
Bibliografia
Fernandez AZ, Tablante A, Bartoli F, Beguin S, Hemker HC, Apitz-Castro R. Expression of biological activity of draculin, the anticoagulant factor from vampire bat saliva, is strictly dependent on the appropriate glycosylation of the native molecule. Biochim Biophys Acta 1998;1425:291-9.
Biochim Biophys Acta. 1998 Oct 23;1425(2):291-9.
ResponderEliminarExpression of biological activity of draculin, the anticoagulant factor from vampire bat saliva, is strictly dependent on the appropriate glycosylation of the native molecule.
Fernandez AZ, Tablante A, Bartoli F, Beguin S, Hemker HC, Apitz-Castro R.
Laboratorio de Trombosis Experimental, Centro de Biofísica y Bioquímica, I.V.I.C. Apartado 21827, Caracas 1020A, Venezuela.
Abstract
Draculin, a glycoprotein isolated from vampire bat (Desmodus rotundus) saliva, is a natural anticoagulant which inhibits activated coagulation factors IX (IXa) and X (Xa). The observation that under captivity conditions, the anticoagulant activity present in vampire bat saliva is dependent upon the salivation protocol, led us to investigate the possible relationship between the expression of biological activity of native draculin and the post-translational glycosylation of the protein backbone. Daily salivation of vampire bats yields a saliva that progressively decreases in anticoagulant activity, without any significant change in overall protein content, or in the amount of protein specifically recognized by a polyclonal anti-draculin antibody. Anticoagulant activity of the saliva is restored after a 4-day period of rest. Besides the marked difference in anticoagulant activity, purified native draculin, obtained from high- and low-activity saliva, shows significant differences in: (a) composition of the carbohydrate moiety, and (b) Glycosylation pattern. Furthermore, controlled chemical deglycosylation of native draculin, under conditions that do not affect the polypeptide backbone, progressively leads to complete loss of the biological activity. Our present results implicate that correct glycosylation of draculin is a seminal event for the expression of the biological activity of this glycoprotein.