[Monomerization of the fragment D dimer of stabilized fibrin by a secretion from the medicinal leech salivary gland]. / Monomerizatsiia dimera fragmenta D stabilizirovannogo fibrina sekretom sliunnykh zhelez meditsinskoi piiavki.

The salivary gland secretion of the medicinal leech catalyzes the conversion into monomeric form of the fragment D dimer, the product of limited proteolysis of stabilized fibrin. Analysis of N-terminal sequences revealed identical fragments for the D-dimer gamma-gamma-chains and the D-monomer gamma-chains formed via this reaction and established the presence of only one N-terminal amino acid (Ser). These results provide evidence for the preservation of integrity of the polypeptide chains during monomerization of the D-dimer.

[Study of the structure of the photosynthetic reaction center of the green thermophilic bacteria Chloroflexus aurantiacus]. / Izuchenie structury fotosinteticheskogo reaktsionnogo tsentra zelenoi termofil'noi bakterii Chloroflexus aurantlacus.

Analysis of the Chloroflexus aurantiacus reaction centre (RC) using both protein and recombinant DNA techniques resulted in determination of its polypeptide composition and the primary structures of its two subunits. A model of the polypeptide chains' folding in the membrane is suggested based on: i) homology between L- and M-subunits of Chloroflexus aurantiacus RC and their counterparts in purple bacteria; ii) comparison of their hydropathy plots, and iii) data on the tertiary structures of purple bacteria RCs. The role of a number of functionally important amino acid residues in the RC electron transport activity is discussed. Limited proteolysis of the RC under non-denaturing conditions was used to determine the contribution of the N-terminal regions to its thermal stability.

[Primary structure of the basic nuclear protein from spermatozoa of the mollusk Illex argentinus and its comparison with the structure of sperm proteins in other animals]. / Pervichnaia struktura osnovnogo iadernogo belka iz spermatozoidov golovonogogo molliuska Illex argentinus i sravnenie ee so strukturami spermal'nykh belkov drugikh zhivotnykh.

The spermatic protein of chromatin I2 of squid Illex argentinus was separated by HPLC into two components I2-1 and I2-2. Amino acid sequences of the major portion of protein I2-1 (52 residues) and the N-terminal sequence of protein I2-2 (21 residues) were determined. Arginines in protein I2-1 are arranged in clusters typical of protamines; the first cluster is in the N-terminus, the longest heterogeneous basic cluster is in the central part of the protein chain, the C-terminal part of the molecule contains two clusters of three hydroxyamino acids each. The N-terminal sequences of illexins I2-1 and I2-2 (1-14 residues) are highly homologous. Homologous regions were found in illexin I2-1, tunnin of tuna fish and avian gallin thus defining the notion of proteins of an intermediate type from mollusc spermatozoa chromatin exemplified by the squid protamine-like protein.

Immunoaffinity isolation of Na,K-ATPase alpha 3 isoform from pig kidney.

The Na,K-ATPase alpha 3 isoform of the catalytic subunit has been isolated from pig kidney microsomes. The procedure employs immunoaffinity chromatography on Sepharose 4B covalently coupled with monospecific antibodies a-II against the synthetic peptide including the putative alpha 3 N-terminus. The structural analysis provides unambiguous proof that the isolated protein corresponds to the third transcript for the alpha 3 isoform. The N-terminal amino acid sequence determined. Met-Gly-Asp-Lys-Lys-Asp-Asp, shows that unlike the alpha 1 and alpha 2 proteins, the mature Na,K-ATPase isoform lacks post-translational proteolytic processing.

[Amino acid sequence of various peptides of tryptophanyl-tRNA-synthetase from bovine pancreas]. / Aminokislotnaia posledovatel'nost' nekotorykh peptidov triptofanil- tRNK-sintetazy iz podzheludochnoi zhelezy krupnogo rogatogo skota.

Method of isolation of the bovine pancreas tryptophanyl-tRNA synthetase is improved and a protein with greater than or equal to 99% purity, according to PAGE-SDS, is obtained. The pure enzyme is digested with clostripain and the hydrolysate is separated by FPLC anion-exchange chromatography followed by reversed phase HPLC. Amino acid sequences of 6 individual peptides, including C-terminal one, were determined by the automated Edman degradation. A peptide is also revealed which is encoded with the low degeneracy.

[Use of electroblotting as a method for preparing samples of proteins and their fragments for microsequencing]. / Primenenie élektroblottinga v kachestve metoda polucheniia obraztsov belkov i ikh fragmentov dliia mikrosekvenirovaniia.

Gel electrophoresis in the presence of sodium dodecyl sulphate followed by electroblotting was employed in sample preparation for microsequencing proteins and protein fragments. Three types of solid supports were compared: glass fiber filters modified by aminopropyltriethoxysilane or covered with polybrene, and polyvinylidenedifluoride membranes. N-Terminal amino acid sequences of several proteins (Mr 14-140 kDA were determined on a gas-phase sequencer with the standard programme; 20-200 pmoles of the protein can be assayed by this method.

Photosynthetic reaction centre of Chloroflexus aurantiacus. Primary structure of M-subunit.

The M-subunit primary structure of the reaction centre (RC) from Chloroflexus aurantiacus composed of 306 amino acid residues has been determined by parallel analysis of the protein and corresponding DNA. The blocked N-terminus as well as replacement of the essential histidine liganding Mg of an accessory bacteriochlorophyll in purple bacteria by leucine distinguishes the M-subunit of Chloroflexus RC from that of purple bacteria.

Photosynthetic reaction centre of Chloroflexus aurantiacus. I. Primary structure of L-subunit.

The L-subunit primary structure of the reaction centre from Chloroflexus aurantiacus composed of 310 amino acid residues has been determined by parallel analysis of the protein and corresponding DNA. Significant homology between this protein and L-subunits from reaction centres of purple bacteria is observed. This implies close similarity in the tertiary structure of these proteins.