9 research outputs found
Inhibition of Horse Liver Alcohol Dehydrogenase by Methyltin Compounds
The study of inorganic tin (SnCl2, SnCl4) and methyltin compounds (MeSnCl3, Me2SnCI2, Me3SnCl)
effects on the enzymatic activity of alcohol dehydrogenase (ADH) in the reaction of ethanol oxidation has
been carried out. The experimental results of the study show that inorganic tin and methyltin substances
induce slight inhibition of the catalytic activity of horse liver alcohol dehydrogenase (HLADH), unable to be
improved during pre-incubation with the enzyme. The conditions for carrying out the kinetic investigation of
the mentioned phenomenon were optimized and as it turned out the mechanism of methyltin trichloride
action, as the most effective methyltin inhibitor, is more complex than the proposed interaction of the metal
atom with SH-groups of the enzyme protein. It was demonstrated that the tin compounds act in the same
manner as methylmercury compounds and might serve as oxidative agents towards the co-enzyme NADH.
Kinetic data on MeSnCl3 were calculated. Data acquired on NAD-dependent ADH from horse liver and those
regarding NAD-dependent LDH from sturgeon liver were compared
Inhibition of Horse Liver Alcohol Dehydrogenase by Methyltin Compounds
ABSTRACT The study of inorganic tin (SnCI2, SnCt4) and methyltin compou.nds (MeSnC13, Me2SnCI, Me3SnC1) effects on the enzymatic activity of alcohol dehydrogenase (ADH) in the reaction of ethanol oxidation has been carried out. The experimental results of the study show that inorganic tin and methyltin substances induce slight inhibition of the catalytic activity of horse liver alcohol dehydrogenase (HLADH), unable to be improved during pre-incubation with the enzyme. The conditions for carrying out the kinetic investigation of the mentioned phenomenon were optimized and as it turned out the mechanism of methyltin trichloride action, as the most effective methyltin inhibitor, is more complex than the proposed interaction of the metal atom with SH-groups of the enzyme protein. It was demonstrated that the tin compounds act in the same manner as methylmercury compounds and might serve as oxidative agents towards the co-enzyme NADH. Kinetic data on MeSnCI3 were calculated. Data acquired on NAD-dependent ADH from horse liver and those regarding NAD-dependent LDH from sturgeon liver were compared
VEGF- and VEGFR2-Targeted Liposomes for Cisplatin Delivery to Glioma Cells
Targeted
delivery of anticancer drugs to brain tumors, especially
glioblastoma multiforme, which is the most frequent and aggressive
type, is one of the important objectives in nanomedicine. Vascular
endothelial growth factor (VEGF) and its receptor type II (VEGFR2)
are promising targets because they are overexpressed by not only core
tumor cells but also by migrated glioma cells, which are responsible
for resistance and rapid progression of brain tumors. The purpose
of the present study was to develop the liposomal drug delivery system
combining enhanced loading capacity of cisplatin and high binding
affinity to glioma cells. This was achieved by using of highly soluble
cisplatin analogue, <i>cis</i>-diamminedinitratoplatinumÂ(II),
and antibodies against the native form of VEGF or VEGFR2 conjugated
to liposome surface. The developed drug delivery system revealed sustained
drug release profile, high affinity to antigens, and increased uptake
by glioma C6 and U-87 MG cells. Pharmacokinetic study on glioma C6-bearing
rats revealed prolonged blood circulation time of the liposomal formulation.
The above features enabled the present drug delivery system to overcome
both poor pharmacokinetics typical for platinum formulations and low
loading capacity typical for conventional liposomal cisplatin formulations