Asunto(s)
Contaminantes Ambientales/efectos adversos , Neoplasias Gástricas/etiología , Adulto , Factores de Edad , Estudios de Cohortes , Femenino , Humanos , Masculino , Persona de Mediana Edad , Federación de Rusia , Factores Sexuales , Agrupamiento Espacio-Temporal , Neoplasias Gástricas/epidemiologíaRESUMEN
A method for simultaneous registration of planar bilayer lipid membrane (BLM) DC conductance G, capacitance C, surface potential difference delta phi and transversal elasticity module E is developed. C, delta phi and E are proportional to the amplitude of the first, second and third harmonics of capacitance current respectively. A comparative study of the interaction of BLM with very low density lipoproteins (VLDL), influenza virus matrix protein (M-protein) and yeast invertase was carried out. The kinetics of delta phi, E and G changes at different concentrations of VLDL, and dependence of delta phi and G on M-protein and invertase concentration was investigated. It is shown for VLDL invertase and M-protein that the changes in delta phi and E occur before the change in G. The method used permits to study peculiarities of individual stages of interaction between charge particles, supramolecular structures and lipid membranes.
Asunto(s)
Conductividad Eléctrica , Membrana Dobles de Lípidos , Lipoproteínas , Proteínas , Viscosidad , Fenómenos Químicos , Química Física , Potenciales de la MembranaRESUMEN
It was shown that under conditions of regulation of secreted enzyme synthesis by its concentration in microorganisms, the repression of synthesis of the enzyme protein polypeptide chain and the concomitant partial repression of labelled amino acid transport into the cells occur. The regulatory effect can be exerted in the absence of transcription as well. These effects are not realized at the post-transcription or post-translation levels.
Asunto(s)
Represión Enzimática , Enzimas/biosíntesis , Aminoácidos/metabolismo , Aspergillus oryzae/metabolismo , Transporte Biológico , Biosíntesis de Proteínas , Saccharomyces/metabolismo , Transcripción GenéticaAsunto(s)
Membranas Artificiales , Fenotiazinas , Electroquímica , Liposomas , Propiedades de SuperficieRESUMEN
By using a fluorescent 3-metoxybenzatrone probe the binding of the phenothiazine series drugs (chlorpromazine, triftazine, aethaperazine) with phospholipid vesicles--liposomes, was investigated. Cholesterol is shown not to affect the binding of these drugs with liposomes. The surface charge of liposomes influences only the combination with the chlorpromazine membranes. With a higher positive charge of the membranes the binding of chlorpromazine diminishes in force.
Asunto(s)
Antipsicóticos/metabolismo , Liposomas/metabolismo , Proteínas de la Membrana/metabolismo , Animales , Embrión de Pollo , Clorpromazina/metabolismo , Colesterol/metabolismo , Colorantes Fluorescentes , Ácidos Linoleicos/metabolismo , Liposomas/aislamiento & purificación , Perfenazina/metabolismo , Fosfolípidos/aislamiento & purificación , Unión Proteica/efectos de los fármacos , Relación Estructura-Actividad , Propiedades de Superficie , Trifluoperazina/metabolismoRESUMEN
Histones of Endomyces magnusii and Neurospora crassa were found to consist of four main fractions similar to calf thymus histones in their electrophoretic mobilities, molecular sizes and chromatographic behaviour on Akrilex P-60. Two of them are homologous to the most conservative histones H3 and H4. Other two fractions correspond to the histones H2A and H2B; however, they have some pecularities. A fraction of N. crassa histones corresponding to the H2B was isolated in a homogeneous state by means of gel filtration. It appeared to be very similar to calf thymus histone H2B in its amino acid composition.