Лаборатория межклеточных взаимодействий НИИ эпидемиологии и микробиологии им. Н.Ф.Гамалеи РАМН, Москва Резюме. С использованием молекулярной ультрафильтрации и дифференциальной спектрофотометрии в ультрафиолете оценивали конформационные изменения человеческого сывороточного γ глобулина при связывании катионов меди и цинка. Содержание свободных металлов в фильтрате оценивали по реакции с диэтилдитиокарбаматом натрия и о фенантролином, соответственно. Показана общность биологических свойств меди и цинка в условиях их связывания с молекулой белка и установлены существенные разли чия между катионами в использованной экспериментальной системе. Так, подтверждена более высокая активность меди на внешних связях молекулы γ глобулина и тропность цинка к внутренним областям белковой глобулы. Описаны сайты связывания металла, различающиеся параметрами взаимодействия с катионами и своей пространственной локализацией. Предложены подходы к анализу динамики заполне ния металлом сайтов разной пространственной локализации. Обсуждаются вопросы конформационного состояния молекулы γ глобулина в ходе связывания катионов, а также перспективы использования полу ченных данных в клинико иммунологических исследованиях.

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Objective. The work was performed with the purpose to study susceptibility of S. aureus bacteria to the action of the standard spectrum of antibiotics in presence of zinc ions used on the disks with antibiotics or on the lawn of the bacterial culture preliminarily to antibiotics treatment.Materials and methods. Suspensions of S. aureus bacteria which contained 108 CFU/ ml were sown by the lawns into the standard Petri dishes coated with the supplemented Nutrient Agar. 30 min later the standard disks with antibiotics were passed on the surface of the lawn, and zinc sulfate was added by the drops of the volume of 5 μl on the surface of the disk. Then the dishes with bacterial cultures were incubated for 24 hrs at 37°C followed by measuring diameter of the area of culture growth inhibition. In some tests preliminarily to the disks with antibiotics passing the places of following disks application were treated with the zinc sulfate for 10 min at the room temperature.Results and discussion. In presence of 1.0 μg/ml of zinc ions on the disk with antibiotics protective action of the metal towards the bacteria was registered at 2.9 per cent observations. In presence of one, four or eight zinc ions per one molecule of antibiotic protective action was registered at 1.4-5.7 per cent observations. Treatment with zinc ions of the surfaces of lawns followed by the disks installation resulted in 27.3-45.5 per cent observations of reducing diameter of the area of bacterial growth inhibition.Conclusion. The treatment of the surface of the lawn of S. aureus bacteria with zinc ions cause protection of the bacteria from the following inhibitory antibiotics action.

Aim. The work was performed with the purpose to study a hemolytic activity in the culture of S.pyogenes under the inhibitory action of millimolar concentrations of zinc ions.Materials and methods. Suspensions of S.pyogenes bacteria which contained 108 CFU/ml were sown by the lawns into the standard Petri dishes coated with the supplemented Blood Nutrient Agar. 30 min later the salt solutions of zinc or copper which contained the metals at the concentrations ranged between 5 x 10-3 M to 5 x 10-1 M were added by the 5 μl drops on the surfaces of the lawns with use of 36-channel stamp replicator. Then the dishes with bacterial cultures were incubated for 24 hrs at 37°C followed by measuring diameter of the area of culture growth inhibition and of the area of inhibition of hemolysis. The study was performed with use of controls towards measuring the state of bacterial cells obtained from different zones of the areas.Results. In presence of the zinc ions concentrations ranged between 50 to 500 mM the area of the growth inhibition of S.pyogenes was surrounded on the lawn of the bacterial culture by the area of the inhibition of hemolysis where the growth inhibition of S.pyogenes was not registered. Copper ions did not form such an area of the hemolysis inhibition.Conclusion. Inhibitory action of zinc ions on the hemolytic S.pyogenes activity in the culture seems to be specific and reversible, and is discussed in a context of the antivirulent zinc ions properties.

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