RESUMO
The effect of mutations in various genes whose products are involved in chromosome organization on the mutagenesis in a double superunstable y2nsscme system was studied. Among these mutations were those in loci zeste, e(y) e(y) 1,2 and 3, responsible for long-distance interactions in chromosomes, and those in the loci E(z), Su(z), Scm, and Psc, whose protein products take part in chromatin compaction. Many of the mutations studied markedly affect the spectrum and the frequency of mutations in the system, in particular, the frequency of double events. The results suggest that the spatial organization of chromosomal domains plays a role in intrachromosomal recombination and gene conversion, since these processes were shown earlier to be dominant in the mutagenesis of a double superunstable system. Some of the mutations under study also modify the phenotypic manifestation of the y2nsscme allele.
Assuntos
Cromossomos , Drosophila melanogaster/genética , Mutação , Recombinação Genética , Alelos , Animais , Cromatina , Proteínas de Ligação a DNA/genética , Proteínas de Drosophila , Feminino , Masculino , FenótipoRESUMO
After denaturation by phenol or acid ethanol bacterial metalloproteinases secreted by Bacillus thermoproteolyticus and Bacillus megaterium cells can be renatured by dissolution in 99.7% formic acid with subsequent dilution of the solution and its neutralization with an appropriate amount of an alkali. Renaturation is optimal at pH 9.0 in the presence of 30% glycerol as stabilizer, Ca2+ and Zn2+ ions needed for the formation of a native structure and reconstitution of the enzyme catalytic center. The active enzyme yield is 60-80%. Reactivated metalloproteinases retain their enzymatic properties, amino acid composition and molecular mass. Under these conditions autolysis of metalloproteinases does not significantly influence their renaturation.
Assuntos
Bacillus megaterium/enzimologia , Bacillus/enzimologia , Metaloendopeptidases/metabolismo , Sequência de Aminoácidos , Aminoácidos/análise , Cálcio/metabolismo , Ativação Enzimática , Concentração de Íons de Hidrogênio , Dados de Sequência Molecular , Desnaturação Proteica , Especificidade por Substrato , Zinco/metabolismoRESUMO
Morphological parameters of the red cells were studied in 121 patients with typhoid-paratyphoid conditions. To obtain objective clinical data the authors studied the effect of LPS S. anatum on the intact red cells of healthy persons. The correlation of morphological disorders in the red cells of the patients and the controls revealed a significant role of intoxication in their origin. The research conducted revealed a relationship between the disorders in the erythrocyte membranes and the development of anemia in the patients.