RESUMEN
We examined the effects of chondroitinases on the release of dermatan sulfate (DS)-induced arginine amidase (AA) from rabbit ear artery. DS-induced AA release was significantly decreased by treatment with chondroitinase ABC (ABCase) in the rabbit ear artery. On the other hand, Chondroitinase ACII (ACIIase) enhanced spontaneous and DS-induced AA release. Heat-inactivated ABCase and ACIIase did not affect spontaneous and DS-induced AA release. Furthermore, ABCase, but not ACIIase and heat-inactivated chondroitinases, degraded DS. These results indicate that the facilitatory effect of DS-induced AA release from the rabbit ear artery is affected by the molecular size of DS.
Asunto(s)
Anticoagulantes/farmacología , Arterias/efectos de los fármacos , Condroitín Liasas/farmacología , Dermatán Sulfato/metabolismo , Serina Endopeptidasas/metabolismo , Animales , Arterias/metabolismo , Condroitina ABC Liasa/farmacología , Dermatán Sulfato/química , Oído , Conejos , Relación Estructura-ActividadRESUMEN
F1-ATPase is a rotary motor protein in which the central γ-subunit rotates inside the cylinder made of α3ß3 subunits. To investigate interactions between the γ shaft and the cylinder at the molecular scale, load was imposed on γ through a polystyrene bead by three-dimensional optical trapping in the direction along which the shaft penetrates the cylinder. Pull-out event was observed under high-load, and thus load-dependency of lifetime of the interaction was estimated. Notably, accumulated counts of lifetime were comprised of fast and slow components. Both components exponentially dropped with imposed loads, suggesting that the binding energy is compensated by the work done by optical trapping. Because the mutant, in which the half of the shaft was deleted, showed only one fast component in the bond lifetime, the slow component is likely due to the native interaction mode held by multiple interfaces.
Asunto(s)
Proteínas Motoras Moleculares/metabolismo , ATPasas de Translocación de Protón/metabolismo , Adenosina Trifosfato/metabolismo , Fenómenos Biofísicos/fisiología , Modelos Moleculares , Conformación Proteica , ATPasas de Translocación de Protón/fisiología , Rotación , TorqueRESUMEN
1. We examined the secretion of arginine amidase activity from rabbit aorta and ear arteries. 2. The amount of arginine amidase activity spontaneously secretion from the aorta was significantly less than that secreted from the ear artery. Dermatan sulphate significantly facilitated the secretion of arginine amidase activity from both the aorta and ear artery. 3. The dermatan sulphate-enhanced secretion of arginine amidase activity from the aorta and ear artery was reduced by denudation of the endothelium. 4. These findings may indicate that spontaneous release of arginine amidase activity from vascular smooth muscle and the enhancement of secretion of arginine amidase activity produced by dermatan sulphate depends on the endothelium.