Detection of annexin IV in bovine retinal rods

The fraction of proteins capable of binding to photoreceptor membranes in a Ca²⁺-dependent manner was isolated from bovine rod outer segments. One of these proteins with apparent molecular mass of 32 kD (p32) was purified to homogeneity and identified as annexin IV (endonexin) by MALDI-TOF mass-spectrometry. In immunoblot, annexin IV purified from bovine rod outer segments cross-reacted with antibodies against annexin IV from bovine liver. This is the first detection of annexin IV in vertebrate retina.     

Milk Ultrafiltrate as a Promising Source of Angiogenin

The use of membrane technologies in the production of curd (soft cheese for children) is associated with the appearance of up to 80% of angiogenin in the ultrafiltrate. An electrophoretically homogeneous preparation of angiogenin (MW 17 kDa) was obtained from milk ultrafiltrate by two-stage ion-exchange chromatography. The yield of the angiogenin was 60%, which corresponds to a 586-fold purification of the raw material. The obtained preparation retained stability in the course of lyophilization and could be stored at 4°C for a long time without decomposition.     

Prevalence of widespread BRCA1 gene mutations in patients with familial breast cancer from St. Petersburg

Ten variants different from the canonical nucleotide sequence (GenBank, U14680) has been identified when studying the mutation spectrum in gene BRCA1. Six of them (5382insC, 2963del10, 3819de15, 3875del4, 2274insA, and R1203X) cause premature termination of protein synthesis, thus predisposing to breast cancer. A missense mutation E1250K is presumed to be a factor of predisposition to cancer. We classified three variants of nucleotide sequence found in some patients as DNA polymorphisms S694S, L771L, and E1038G. The 5382insC and 3819de15 mutations have been detected in four and two families, respectively. Five of the mutations detected have not been found in Russia before. However, all mutations except for 2963del10 have been found in other populations of the world, which indicates their long evolutionary history. Two mutations found in patients from St. Petersburg (5382insC and 3875de14) have also been found in oncological patients from other regions of the Russian Federation.     

Effect of Azospirillum brasilense lectin on the kinetics of lymph nodes cell populations and cytokine status in experimental animals

The complex study of the influence of A. brasilense Sp 7 lectin with carbohydrate specificity to L-fucose and D-galactose on the dynamics of cell populations in different structural functional zones of the white mice mesentery, as well as on the capacity of immunocompetent cells of mesenterial lymph nodes for synthesizing cytokines (interleukin-1, interleukin-6 and tumor necrosis factor), was carried out. A single oral administration of bacterial lectin in a dose of 4.5 micrograms produced a pronounced immunostimulating effect.     

Milk ultrafiltrate as a promising source of angiogenin

The use of membrane technologies in the production of soft cheese (children's food) is associated with the appearance of up to 80% of angiogenin in the ultrafiltrate. An electrophoretically homogeneous preparation of angiogenin (MW approximately 17 kDa) was obtained from milk ultrafiltrate by two-stage ion-exchange chromatography. The yield of the angiogenin was approximately 60%, which corresponds to a 586-fold purification of the raw material. The obtained preparation retained stability in the course of lyophilization and could be stored at 4 degrees C for a long time without decomposition.     

The replication of Escherichia coli chromosome can be initiated by integrated ColE1-type plasmids

Summary When integrated in the chromosome of E. coli by site-specific recombination of , the ColE1 type replicator provokes the phenotypic suppression of CRT46 dnaA strain. The level of this suppression depends on the orientation of ColE1 replicator in the chromosome of bacteria. Integrative plasmids (intmids) coexist in both autonomous and extrachromosomal states in the same cell.     

Comparative analysis of the effects of synthetic derivatives of batrachotoxin on sodium currents in frog node of Ranvier

1. In voltage-clamp experiments on frog myelinated nerve fibers, the effects of nine synthetic derivatives of batrachotoxin (BTX) obtained from 7,8-dihydrobatrachotoxinin A (DBTX-A) on Na+ currents (INa) have been investigated. 2. Both of 20 alpha-esters of DBTX-A with 2,4,5-trimethylpyrrol-3-carboxylic acid (DBTX-P) and benzoic acid (DBTX) at a 10(-5) M concentration caused modification of INa qualitatively similar to that induced by BTX. 3. The quaternary derivative of DBTX (QDBTX) produced such changes in INa only at a 5.10(-4) M concentration, apparently due to its much lower lipid solubility. 4. Replacement of a -CH2- by a -C = O. group in the homomorpholine ring near the tertiary nitrogen atom abolished the DBTX activity, strongly suggesting the necessity of tertiary nitrogen protonation for the toxin interaction with the channel receptor. 5. Transfer of an 11-hydroxygroup from the alpha- to the beta-position in the DBTX molecule did not decrease its activity in spite of the fact that in the beta-position this group is sterically very hindered. The activity of 11 beta-DBTX is at variance with the prediction of Codding's (1983) "oxygen triad" hypothesis. 6. DBTX-A and compounds obtained from DBTX by oxidation of the 11 alpha-hydroxygroup (K-DBTX), acetylation (Ac-DBTX), or reduction of the hemiketal moiety (H2DBTX) even at a concentration as high as 10(-3) M were able to modify only a very small fraction of the Na channels. However, a clear-cut reversible blocking action on both normal and modified Na channels was observed. 7. These results led us to conclude that BTX modifies the Na channels only in the charged form and hemiketal and 20 alpha-ester moieties provide adequate disposition of toxin on the receptor surface. The inability of H2DBTX, DBTX-A, and K-DBTX and Ac-DBTX to modify most of the Na channels can be explained by a low "probability of correct disposition" of these ligands on the receptor surface.     

Construction of recombinant plasmid carrying the lambda DNA fragment responsible for prophage integration.

The recombinant DNA molecules were constructed from plasmid RSF2124 and the EcoRI fragment of lambda DNA containing the genes responsible for prophage integration. The presence of these genes in recombinant plasmids was detected genetically. lambda int-gene was shown to be expressed in either orientation of insertion in the plasmid. We found that recombinant plasmid was able to integrate into chromosome of lambda lysogens. The integration of plasmid into host chromosome was demonstrated by contransduction of chromosome and plasmid markers using generalized transducer P1 and by specialized transduction with lambda phages.