A new role for PGRP-S (Tag7) in immune defense: lymphocyte migration is induced by a chemoattractant complex of Tag7 with Mts1

PGRP-S (Tag7) is an innate immunity protein involved in the antimicrobial defense systems, both in insects and in mammals. We have previously shown that Tag7 specifically interacts with several proteins, including Hsp70 and the calcium binding protein S100A4 (Mts1), providing a number of novel cellular functions. Here we show that Tag7–Mts1 complex causes chemotactic migration of lymphocytes, with NK cells being a preferred target. Cells of either innate immunity (neutrophils and monocytes) or acquired immunity (CD4⁺ and CD8⁺ lymphocytes) can produce this complex, which confirms the close connection between components of the 2 branches of immune response.     

The study of the growth of tylosin producer using differential centrifugation of mycelium in a sucrose density gradient

The mycelium of Streptomyces fradiae was fractionated by differential centrifugation in a sucrose density gradient (SDG) using various samples of the inoculation material and aliquots of the cultural broth taken in the course of tylosin production. The mode of mycelium distribution in SDG made it possible to select the most active inoculation material. The mycelium was redistributed from sucrose layers with a high density to those with a lower density in the course of fermentation. The fractions differed in the antibiotic activity but none of them had an activity higher than in the control centrifuged in 30% sucrose and washed off just like the fractions. Therefore, mycelium fractionation in SDG would not elevate its antibiotic activity. The paper presents the cytological characteristics of different fractions changing in the course of fermentation.     

A method of determining the primary structure of oligodeoxyribonucleotides

Sanger method was modified to fulfill the requirements of sequencing of oligodeoxyribonucleotides. E. coli DNA polymerase I Klenow fragment was used for all the reactions. The method consists of three steps made in succession in one tube: 1. Optional hydrolysis of a 5'-labeled oligodeoxyribonucleotide primer in order to get a set of primers of different lengths. 2. Elongation of the produced set of primers in the presence of a template, natural dNTPs and chain terminating dNTP analogs. 3. Hydrolysis of the products of the previous step in order to remove the unterminated molecules. Change of steps in achieved just by varying the reaction conditions without any product purification. The method in insensitive to the presence of admixture of oligonucleotides which is not complementary to the primer or to the template.     

Properties of cloned promoters

Strong early bacteriophage T7 promoters A2 and A3 and also A2 and lac UV5 promoters with altered segments downstream the initiation of RNA start point were cloned using specially constructed plasmid vectors pBRS188 and PBRS240. The relative signal strengths of these promoters in vivo and in vitro were evaluated and the kinetic parameters of their interaction with RNA polymerase were determined. It has been shown that the nucleotide sequence of the transcribed region plays a significant role in specific promoter-RNA polymerase interaction and that the rate-limiting step of RNA synthesis initiation is different for various promoters.     

A Study of the Structure of Trypsin-Like Serine Proteinases. 2. A Study of Tryptophan Fluorescence in Variants of Miniplasminogen with an Altered Primary Structure

Biophysics - Abstract—Variants of miniplasminogen with an altered primary structure have been designed to study previously described changes in tryptophan fluorescence during plasminogen...     

A kinetic model of the cleavage of permutational variants of the antigenomic HDV-ribozyme

The kinetic characteristics have been studied for noncircularly permuted variants of the human hepatitis delta virus (HDV) antigenomic ribozyme to find out the cause of the two-phase kinetics of the self-cleavage reaction. Different ways of reaction initiation, suboptimal conditions, and jumpwise changes of reaction conditions have been used, and the temperature dependences have been studied. A correlation has been shown between the apparent kinetic constant of the first reaction phase and the portion of the ribozyme molecules that self-cleaved during the first phase. Partial restoration of the initial reaction characteristics has been shown by the reinitiation of reaction being stopped after completing the first phase. On the basis of all the data obtained, a scheme of the self-cleavage reaction has been proposed including: (i) activation of the ribozyme with energy of 40-50 kcal/mol and a characteristic time of several deciminutes under optimal reaction conditions; (ii) fast and reversible reaction of the phosphodiester bond cleavage; (iii) reaction leading to isomerization of the 3',5'-phosphodiester bond to the 2',5' bond in the self-cleavage site with a characteristic activation time of tens of minutes; and (iv) practically irreversible conformational change leading to fixation of the cleavage by immobilization of the 5'-terminal nucleotide of the product in the center of the formed structure and displacement of the 3'-terminal nucleotide to the periphery. The latter process has a characteristic time of tens of minutes and a low activation energy.     

Viscumin modulates neutrophil respiratory burst, caused by a chemotactic peptide

The ability of viscum at different concentrations to modulate the respiratory burst in neutrophils, induced by the chemotactic peptide N-formyl-methionyl-leucyl-phenylalanine was studied. This does not exclude the possibility that viscum can interact with the receptor of this peptide. The analysis of the primary structure of viscum revealed elements structurally analogous to the chemotactic peptide. It is assumed that viscum can exhibit the properties an antagonist of the receptor of N-formyl-methionyl-leucyl-phenylalanine, and the mechanism of action of viscum depends on its concentration.     

<Emphasis Type="Italic">Pseudomonas aeruginosa</Emphasis> inhibits <Emphasis Type="Italic">in-vitro Candida</Emphasis> biofilm development

Background  

Elucidation of the communal behavior of microbes in mixed species biofilms may have a major impact on understanding infectious diseases and for the therapeutics. Although, the structure and the properties of monospecies biofilms and their role in disease have been extensively studied during the last decade, the interactions within mixed biofilms consisting of bacteria and fungi such as Candida spp. have not been illustrated in depth. Hence, the aim of this study was to evaluate the interspecies interactions of Pseudomonas aeruginosa and six different species of Candida comprising C. albicans, C. glabrata, C. krusei, C. tropicalis, C. parapsilosis, and C. dubliniensis in dual species biofilm development.     

Molecular determinants of caste differentiation in the highly eusocial honeybee <Emphasis Type="Italic">Apis mellifera</Emphasis>

Background  

In honeybees, differential feeding of female larvae promotes the occurrence of two different phenotypes, a queen and a worker, from identical genotypes, through incremental alterations, which affect general growth, and character state alterations that result in the presence or absence of specific structures. Although previous studies revealed a link between incremental alterations and differential expression of physiometabolic genes, the molecular changes accompanying character state alterations remain unknown.     

Mitochondrial haplotype diversity in the tortoise species <Emphasis Type="Italic">Testudo graeca</Emphasis> from North Africa and the Middle East

Background  

To help conservation programs of the endangered spur-thighed tortoise and to gain better insight into its systematics, genetic variation and evolution in the tortoise species Testudo graeca (Testudines: Testudinidae) was investigated by sequence analysis of a 394-nucleotide fragment of the mitochondrial 12S rRNA gene for 158 tortoise specimens belonging to the subspecies Testudo graeca graeca, Testudo graeca ibera, Testudo graeca terrestris, and a newly recognized subspecies Testudo graeca whitei. A 411-nucleotide fragment of the mitochondrial D-loop was additionally sequenced for a subset of 22 T. graeca, chosen because of their 12S gene haplotype and/or geographical origin.