Abstract:The influence of benzene and acetone on the liquid-crystal structure of phosphatidylethanolamine(PE)was investigated respectively by method of the small angle X-ray scattering(SAXS).The experi-ments showed that the benzene enabled the tie of PE in liquid-crystal state to change from lamellarphase into cubic phase,then induced it from cubic phase into hexagonal phase,and finally to impel itchanging from hexagonal phase into liquid state.Meanwhile,in this phase transition of the tie removalappeared the red shift. Besides, the acetone was also capable of removing the tie of PE in liquid-crystal state from lamellar phase into cubic phase. Again,the red shift appeared in these transitions of the tie. However, when PE in liquid-crystal state was induced into hexagonal phase, the acetone was unable to impel it from hexagonal phase into liquid phase like benzene, but stabilized it only in hexagonal phase.
Abstract:The inhibitory effects of two synthesized 3-nitrosalicyl-N-dodecylamide and 2-hydroxy-3-N-dodecylamide-pyridine on the respiratory chain had been compared by using heart muscle preparation from pig heart.3-nitrosalicyl-N-dodecylamide showed stronger effect than 2-hydroxy-3-N-dodecylamide-pyridine on all the three Q-related enzymes of NADH-Q reductase,suceinate-Q reductase and QH2-cytochrome c reductase.No any inhibitory effect of this two compounds on the terminal oxidase had been observed.The hydroxy groups in the rings of both compounds may be involved in the inhibitory effect through their disturbance on the hydration and dehydration of ubiquinone.
Abstract:To overcome several disadvantages of the use of superoxide dismutase(SOD)in its native form the surface modification of therapeutically useful enzyme by covalent linkage of nontoxic,nonimmunogenic, and biocompatible polymers has been investigated.Recombinent human Cu/Zn SOD (rh Cu/Zn SOD) obtained from E.coli was coupled chemically with activated polyethylene glycol(PEG).The modified rhCu/Zn SOD,with apparent molecular weight about 60000 daltons,has longer half-life(15 hours), and the remaining enzyme activity is more than 80 per cent. Its stabilities against acid, alkali and heat were increased significantly. The relation between the amount of PEG used and the remained enzyme activity was also reported.
