Phenylalanine hydroxylase of human embryos: its homology with the enzyme from the liver of adults

Phenylalanine hydroxylase (PH) activity was discovered in the liver of 7-12 week old human embryos. Embryonic and adult PHs were identical, as shown by immunoelectrophoresis. Unlike the adult liver PH, the PH content of the extract of cytoplasmic proteins of embryonic liver was reduced but the specific activity was increased more than by one order of magnitude. H (57,000 D) and L (55,000 D) subunits were detected by immunoblotting. The L subunit predominates in the extract of membrane proteins of embryonic liver. Hence, the major part of phenylalanine oxidizing activity in the embryonic liver is related to the enzyme immunochemically identical with the PH of adult liver but differing from it in some structural and functional properties.     

mtDNA diversity in rhesus monkeys reveals overestimates of divergence time and paraphyly with neighboring species

Reconstructions of the human-African great ape phylogeny by using mitochondrial DNA (mtDNA) have been subject to considerable debate. One confounding factor may be the lack of data on intraspecific variation. To test this hypothesis, we examined the effect of intraspecific mtDNA diversity on the phylogenetic reconstruction of another Plio- Pleistocene radiation of higher primates, the fascicularis group of macaque (Macaca) monkey species. Fifteen endonucleases were used to identify 10 haplotypes of 40-47 restriction sites in M. mulatta, which were compared with similar data for the other members of this species group. Interpopulational, intraspecific mtDNA diversity was large (0.5%- 4.5%), and estimates of divergence time and branching order incorporating this variation were substantially different from those based on single representatives of each species. We conclude that intraspecific mtDNA diversity is substantial in at least some primate species. Consequently, without prior information on the extent of genetic diversity within a particular species, intraspecific variation must be assessed and accounted for when reconstructing primate phylogenies. Further, we question the reliability of hominoid mtDNA phylogenies, based as they are on one or a few representatives of each species, in an already depauperate superfamily of primates.      

Nucleotide sequence of the Clostridium thermocellum laminarinase gene.

The sequence presented (1022 bp) shows the Clostridium thermocellum laminarinase gene (lam1) and its flanking regions. The gene lam1 comprises an open reading frame of 726 nt, encoding a 242-aa protein with predicted Mr 27661. The ORF startswith the translation initiation codon ATG. This ATG codon is preceded at a spacing of 7 bp by a potential ribosome binding site (GGAGGT). A putative signal peptide was identified (the potential cleavage site is between position 27-28 aa). The comparison of the primary protein sequence with other beta-1, 3-1, 4-glucanases showed extensive homology for Bacillus amyloliqefaciens and Bacillus subtilis glucanases (identity-46.7%; similarity-57.0%).     

Broiler chicken cecal microbiocenoses depending on mixed fodder

Molecular genetic techniques (NGS sequencing and quantitative PCR) were used to determine the composition of the cecal bacterial community of broiler chickens fed with different mixed fodder. The cecal microbiome exhibited taxonomic diversity, with both typical inhabitants of avian intestine belonging to the families Clostridiaceae, Eubacteriaceae, and Lactobacillaceae and to the phylum Bacteroidetes, and new unidentified taxa, as well as bacteria of the families Lachnospiraceae and Ruminococcaceae, which were previously considered restricted to the rumen microbiota. Contrary to traditional concepts, enterococci and bifidobacteria were among the minor components of the community, lactate-fermenting species were absent, and typical avian pathogens of the genus Staphylococcus were detected but seldom. Members of the family Suterellaceae and the genus Gallibacterium, which are responsible for avian respiratory infections, were also detected. Significant fluctuations of abundance and composition of microbial groups within the cecal community and of the parameters of broiler productivity were found to occur depending on the feed allowance. Cellulose content in the feed had the most pronounced effect on the composition and structure of bacterial communities. Decreased cellulose content resulted in a decrease of bacterial abundance by an order of magnitude and in increased ratios of members of the phylum Bacteroidetes and the family Clostridiaceae, which possess the enzymes degrading starch polysaccharides. Abundance of the normal inhabitants of avian intestine belonging to the genus Lactobacillus and the order Bacillales decreased, while the share of Escherichia and members of the family Sutterellaceae increased, including some species capable of causing dysbiotic changes in the avian intestine. No significant change in the abundance of cellulolytics of the families Ruminococcaceae, Lachnospiraceae, and Eubacteriaceae was observed.     

Mathematical model of proliferative activity in epidermis of the normal skin and of the skin afflicted by psoriasis

A mathematical model of the mitotic activity of epidermis in norm and psoriasis is presented, which consists of a system of two autonomous nonlinear differential equations. A qualitative analysis of the model was done, and numerical solutions at the parameter values corresponding to these state were obtained. It was shown that, in norm, the system can exist only in one stationary equilibrium state of the "focus" type, and in psoriasis, due to an increase in the growing fraction, hyperproliferation, and enhanced migration of keratinocytes, a stable limiting cycle arises from the state of an unstable focus. The existence of two stable states (focus and the limiting cycle) is regulated by a parameter that describes the inhibition of division of maturing cells of suprabasal epidermal layers by the intrinsic tissue-specific transmitters of mitosis of G1-keilon type. The model is consistent with experimental data on the kinetics of cell proliferation in the epidermis in norm and psoriasis and the clinical course of the disease.     

Synchronization of oscillations of proliferation of keratinocytes in psoriatic skin by external periodic force: a mathematical model

A mathematical model of mitotic activity of epidermis in normal skin and skin afflicted with psoriasis is presented as a system of two autonomous nonlinear differential equations. Its qualitative analysis was carried out and numerical solutions were obtained at the parameter values corresponding to these states. It was shown that in the norm, a single stable equilibrium of a "focus" type exists in the system; whereas in psoriasis, owing to an increase in the growing fraction, hyperproliferation, and enhanced migration of interacting keratinocytes, a stable limit cycle arises from the state of unstable focus. In this paper we also report on the results of computer modeling of synchronization of self-excited oscillations of keratinocyte population density in psoriatic lesions by an external periodic force. This synchronization is viewed as a possible mechanism of the clinically observed dependence of psoriasis course on some natural factors of cyclic nature.     

Identification of the membrane form of phenylalanine hydroxylase from the human liver and characteristics of its subunit composition

Phenylalanine hydroxylase was detected among human liver bioptats and autoptats extracted with 0.4% Triton X-100 from the 105,000 g homogenate fraction. In contrast to the membrane form of the rat liver enzyme, human liver phenylalanine hydroxylase is detected both by its enzymatic activity and immunochemically under non-denaturating conditions. The enzymatic activity of phenylalanine hydroxylase makes 5-15% of that of the cytoplasmic fraction and 20-30% of the amount of antigen in the cytoplasmic fraction and 20-30% of the amount of antigen in the cytoplasmic fraction as can be evidenced from rocket immunoelectrophoresis data. Immunoblotting of proteins performed after denaturating electrophoresis of the membrane and cytoplasmic fractions revealed an antigen band with a similar electrophoretic mobility. The subunit composition of the enzyme in both fractions was characterized by two-dimensional electrophoresis with subsequent immunoblotting. It was found that the membrane fraction of the enzyme is represented only by the L-subunit with Mr of 55 kD, whereas the cytoplasmic fraction, besides the predominant L-subunit, also contains 2H-subunits of the enzyme with Mr = 57 kD. These 2H-subunits differ between themselves as well as from the L-subunit by the pI value.     

Identification of alpha-tropomyosin of the human myocardium by two-dimensional electrophoresis, and sequencing]

Two-dimensional electrophoresis of total cardiac muscle extracts allows the detection of about 200 protein fractions. In preliminary studies the fraction D-10 protein was characterized in terms of relative molecular mass, isoelectric point and quantitative composition as alpha-tropomyosin. The similarity of the protein to human alpha-tropomyosin was confirmed by the results of analysis of the N-terminal sequence of the D-10 protein eluate in a gas-phase sequencer.     

Effect of Bacillus subtilis on the rumen microbial community and its components exhibiting high correlation coefficients with the host nutrition, growth, and development

T-RFLP investigation of the microbial community of the ruminal fluid of calves revealed changes in the microbiocenosis resulting from feeding the animals with biofilm-protected Bacillus subtilis cells. In the control animals, which switched from the diary to the vegetable diet, the phylum Firmicutes predominated Firmicutes (55.11 ± 1.97%), in particular the class Clostridia (53.10 ± 2.06%), families Lachnospiraceae (25.93 ± 1.41%) and Clostridiaceae (9.90 ± 1.35%). Members of the phyla Bacteroidetes (11.15 ± 2.88%) and Actinobacteria (9.27 ± 1.95%) were also present. Uncultured forms constituted 17.28 ± 2.01%. The share of bacilli (family Bacillaceae) was below 2% (1.46 ± 0.41%). Introduction of B. subtilis cells into the rumen of experimental animals increased the share of Bacillaceae to 2.80 ± 0.30%. The numbers of Thermoanaerobacteriaceae, Peptostreptococcaceae, and Alicyclobacillaceae increased by an order of magnitude. The numbers of Pseudomonadaceae, Burkholderiaceae, and uncultured Bacteroidetes increased twofold. Increased numbers of the rumen bacteria and protozoa, elevated fatty acid content, and higher ammonia emission indicated increased efficiency of digestion. Some families, including the domineering ones, included the members with different directions of the correlation with the indices of rumen digestion. The introduced bacilli stimulated the phylotypes with the positive correlation coefficients and suppressed those with the negative correlation. This, the rumen ecosystem was modified in the direction of improved digestion. The functional role of the members of the microbial community, for which the correlations were negative, weakly associated, or unassociated with the indices of rumen digestion are discussed.