The nature of a covalent bond between the relaxation protein and ColE1-DNA in the relaxation complex

O-[32P]phosphoserine was found to be the only phosphoamino acid in the acid hydrolysate of the [32P]ColE1 DNA-peptide produced by action of proteases on the ColE1 DNA relaxation complex. This finding suggests that the relaxation protein is bound to ColE1 DNA in the relaxation complex via a phosphodiester linkage between a serine hydroxyl of the protein and the 5'-phosphate of the terminal deoxycytidine residue of the DNA.     

Amplitude fluctuations in the contractile responses of small fragments of rat papillary muscle

Contractile responses of small rat papillary muscle segments (length = 0.25 mm) superfused in a normal Tyrode's solution (t = 35 degrees C) and stimulated at a frequency of 0.16 Hz have been measured, using an original technique. The amplitude of contractile responses was found to fluctuate with the variation of 3.0 +/- 0.4 mu, though the contraction amplitude of the entire muscle remained constant from beat to beat. After the addition of caffeine (6 mM) the variation of contractile responses decreased up to 0.83--0.03 mu, demonstrating a crucial role of sarcoplasmic reticulum in the phenomenon. It is believed that contractility inhibition during calcium overload may be caused by the same reason.     

Microplastics as a New Ecological Niche For Multispecies Microbial Biofilms within the Plastisphere

Microbiology - The distribution, colonization, and biodegradation of primary and secondary microplastics, as well as were effect on the plastisphere ecological systems, are analyzed. The pathways...     

Localization of DNA Sequences Tightly Associated with the Synaptonemal Complex in Compositional Fractions of the Golden Hamster Genome*

Synaptonemal complex (SC) isolated from spermatocyte nuclei after their exhaustive hydrolysis by DNase II contains DNA sequences tightly associated with it (SCAR DNA). Here, the compositional properties of a cloned family of golden hamster SCAR DNA were studied. For this purpose, 27 SCAR DNA clones were hybridized with compositionally fractionated golden hamster genomic DNA. The sequences of the SCAR DNA family were mainly localized in the GC-poor isochore families L1 and L2, which accounted for 63% of hybridization signals. The remaining 37% of signals pertained to the GC-rich isochore families H1 and H2. Thus, SCAR DNA proved to be distributed throughout the genome, irrespective of differences in density and sequence type between isochore families. Moreover, the SCAR DNA sequences containing the regions of homology with LINE/SINE repeats were found in all the isochore families. The compositional localization of SCAR DNA is in agreement with the hypothesis that the SC and SCAR DNA participate in chromatin reorganization during meiosis prophase I, which should result in the attachment of chromatin loops to the lateral elements of SC throughout its length.     

Lability of Stationary and Time-Resolved Optical Properties of the Conformationally Locked CFP Chromophore Derivative

Russian Journal of Bioorganic Chemistry - The solvatochromic behavior of a model compound mimicking the chromophore of cyan fluorescent protein (CFP) in the spectral and time domains has been...     

Participation of acid phospholipids in protein translocation across the bacterial cytoplasmic membrane

Recent observations confirm the participation of acid phospholipids in protein translocation. The hypothesis proposed coupled protein translocation with transmembrane movement of acid phospholipids, their metabolism as a precursor of cell envelope components and recycling. These factors ensure the unidirectional vector value of the secretion, restoration of the membrane site competent for protein translocation and its self-organization.