RESUMEN
In this paper we report the discovery of bacteriolytic activity of an immune system cytokine mediator, interleukin-2. Bacteriolytic activity of interleukin-2 was compared with a well-known bacteriolytic enzyme - chicken egg white lysozyme - by monitoring the lysis of the Gram-negative bacterium Escherichia coli, the Gram-positive coccus Micrococcus luteus, and the Gram-positive spore-forming bacillus Bacillus subtilis. It was found that interleukin-2 has greater specificity to the Gram-negative bacterium E. coli than does lysozyme. In contrast to chicken egg white lysozyme, interleukin-2 does not lyse the Gram-positive coccus M. luteus and the Gram-positive spore-forming bacillus B. subtilis. These results give a new understanding of the biological functions of interleukin-2, a regulatory protein that plays a role in oncological and infectious diseases.
Asunto(s)
Interleucina-2/metabolismo , Bacillus subtilis/metabolismo , Bacteriólisis , Escherichia coli/metabolismo , Humanos , Micrococcus luteus/metabolismo , Muramidasa/metabolismoRESUMEN
In the present work the studies ofbacteriolytic factors from sheep blood plasma have been performed. Three novel enzymes have been identified and characterized. Two of them have a molecular weight 15 +/- 2 kDa and able to lyse the gram-negative Escherichia coli bacteria. The third enzyme has a molecular weight 34 +/- 4 kDa and is able to lyse both gram-negative Escherichia coli and gram-positive Micrococcus luteus bacteria. The bacteriolytic reactions have been studied for all three enzymes; particularly, pH-optima have been identified with respect to the substrate. To identify the enzymes trypsinolysis and consequent MALDI-TOF mass spectrometry studies were performed. The results were compared to data from publicly available databases, such as Swiss-Prot, NCBI, MSDB.
Asunto(s)
Antibacterianos/química , Bacteriólisis , Muramidasa/química , Péptido Hidrolasas/química , Plasma/enzimología , Ovinos/sangre , Animales , Antibacterianos/aislamiento & purificación , Antibacterianos/farmacología , Bacillus subtilis/efectos de los fármacos , Pared Celular/química , Cromatografía en Gel , Cromatografía por Intercambio Iónico , Bases de Datos Factuales , Escherichia coli/efectos de los fármacos , Micrococcus luteus/efectos de los fármacos , Peso Molecular , Muramidasa/aislamiento & purificación , Muramidasa/farmacología , Péptido Hidrolasas/aislamiento & purificación , Espectrometría de Masa por Láser de Matriz Asistida de Ionización DesorciónRESUMEN
Electrochemically induced oxidative damage to DNA was studied with double-stranded calf thymus DNA immobilized directly on a gold electrode surface. Pre-polarization of the DNA-modified electrodes at +0.5 V versus Ag/AgCl reference electrode, in a free from DNA blank buffer solution, pH 7.4, allowed for subsequent detection of direct electrochemical oxidation of adsorbed on gold DNA, in the potential range from +0.7 to +0.8 V. The redox potential of the process corresponded to the potentials of the oxidation of guanine bases in DNA. It is shown that with increasing potential scan rate, v, the mechanism of electrochemical oxidation of DNA changes from the irreversible 4e(-) oxidative damage of DNA at low v to reversible 1e(-) oxidation at high v, keeping the electrochemical activity of the adsorbed DNA layer virtually the same.