Chromomycin A3 (CHR) binding to the duplex d(CAAGTCTGGCCATCAGTC).d(GACTGATGGCCAGACTTG) has been studied using quantitative footprinting methods. Previous NMR studies indicated CHR binds as a dimer in the minor groove. Analysis of autoradiographic spot intensities derived from DNase I cleavage of the 18-mer in the presence of various amounts of CHR revealed that the drug binds as a dimer to the ...

The characteristics of the surface of guinea pig megakaryocytes were investigated with wheat germ agglutinin (WGA). Purified guinea pig megakaryocytes and platelets were incubated with WGA conjugated with rhodamine, cytocentrifuged, and then exposed to Chromomycin A3 for the assessment of ploidy. The fluorescence emission of the DNA-Chromomycin complex was similar to that of fluorescein, and th...

The biosynthesis of chromomycin A3 was investigated using 13C-labeled acetates, methionine and glucose, and 13C,18O-labeled acetate. 13C NMR spectral analysis demonstrated that: Aglycone assembly occurs by combining at least two polyketide chains; three of nine oxygen atoms of the aglycone originate from acetate precursor oxygen atoms; carbon methylations on the aromatic ring at C-7, on the chr...

BACKGROUND The compaction of human sperm chromatin is the result of replacement of approximately 85% of histones with protamines. Germ-line testis/sperm-specific histone 2B (TSH2B) has been detected in only approximately 30% of mature spermatozoa. Its level in the semen of subfertile patients varies; its function is unknown. We evaluated TSH2B in the sperm samples of 23 donors and 49 subfertile...

The cobia, Rachycentron canadum, a species of marine fish, has been increasingly used in aquaculture worldwide. It is the only member of the family Rachycentridae (Perciformes) showing wide geographic distribution and phylogenetic patterns still not fully understood. In this study, the species was cytogenetically analyzed by different methodologies, including Ag-NOR and chromomycin A(3) (CMA(3)...

Three structurally related anticancer drugs, mithramycin, chromomycin A3, and olivomycin, exhibited large differences (greater than 100-fold) in their toxicity towards cultured cells from various species. These differences are species related, as all cell lines from any one species showed similar sensitivity to the three drugs. Of the three species examined, namely, human, mouse, and Chinese ha...

Two populations of Astyanax altiparanae (Garutti & Britski, 2000) of the Água dos Patos stream/SP and lake Igapó/PR were analyzed. All individuals showed 2n = 50, however, different karyotypic formulae were observed. The population of the Água dos Patos stream showed 8m +24sm+6st+12a (NF=88) and the population of lake Igapó, 8m+28sm+4st+10a (NF=90). Nucleolus organizing regions (AgNORs) were ob...

Three populations of the genus Crenicichla, namely Crenicichla iguassuensis, Crenicichla sp 1 and Crenicichla sp 2, from the Iguaçu River, were analyzed cytogenetically, and their nucleolus organizer regions, constitutive heterochromatin distribution and chromomycin A3 markings were studied. Karyotype analyses showed a diploid number of 48 chromosomes, made up of 2 metacentric pairs, 2 submetac...