[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.

[Primary structure of the OSCP-protein, conferring the oligomycin sensitivity to the H+-ATPase complex. II. Hydrolysis of OSCP with proteinase from Staphylococcus aureus and reconstruction of the polypeptide chain]. / Pervichnaia struktura OSCP-belka, pridaiushchego mitokhondrial'nomu H+-ATP-aznomu kompleksu chuvstvitel'nost' k oligomitsinu. II. Gidroliz OSCP proteinazoi iz Staphylococcus aureus i rekonstruktsiia polipeptidnoi tsepi belka.

Hydrolysis of OSCP of bovine heart mitochondria by proteinase from Staphylococcus aureus V8 was followed by isolation of all individual peptides by means of gel-filtration and HPLC. Structural analysis of the peptides allowed to arrange BrCN-fragments and to reconstruct the complete amino acid sequence of the protein. Comparative structural analysis revealed existence of a certain homology between OSCP and delta- and b-subunits of the E. coli H+-ATPase, which are necessary for interaction of catalytic and proton-conducting parts of the bacterial enzyme.

Detailed structural analysis of exposed domains of membrane-bound Na+,K+-ATPase. A model of transmembrane arrangement.

Exposed regions of the alpha- and beta-subunits of membrane-bound Na+,K+-ATPase were in turn hydrolyzed with trypsin. Resistance of the beta-subunit to proteolysis was shown to be due mainly to the presence of disulfide bridge(s) in the molecule. A model for the spatial organisation of the enzyme in the membrane was proposed on the basis of detailed structural analysis of extramembrane regions of both subunits.

[A method of selective isolation of tryptophan- and cysteine-containing peptides by covalent chromatography. Analysis of the topography of the Na+,K+-ATPase alpha-subunit]. / Metod selektivnogo vydeleniia triptofan- i tsisteinsoderzhashchikh peptidov kovalentnoi khromatografiei. Analiz topografii alpha-sub''edinitsy Na+,K+-ATP-azy.

A procedure for highly selective isolation of tryptophan- and cysteine-containing peptides from protein hydrolysates has been developed on the basis of covalent chromatography. It includes incorporation of a thiol group into the tryptophan residues by sequential treatment of peptides with 2-nitrophenylsulfenyl chloride and beta-mercaptoethanol followed by immobilization on the corresponding supports via thiol-disulfide exchange. The technique is applicable to the analysis of the hydrolysate of the Na+, K+-ATPase alpha-subunit obtained by limited trypsinolysis of the membrane-bound enzyme. Fifteen tryptophan- and cysteine-containing tryptic peptides, which comprise the protein portions exposed outside the membrane, have been isolated in addition to those previously identified. This structural information allows unequivocal determination of boundaries of transmembrane segments of the alpha-subunit in the spatial model earlier proposed.

Pig kidney Na+,K+-ATPase. Primary structure and spatial organization.

cDNAs complementary to pig kidney mRNAs coding for alpha- and beta-subunits of Na+,K+-ATPase were cloned and sequenced. Selective tryptic hydrolysis of the alpha-subunit within the membrane-bound enzyme and tryptic hydrolysis of the immobilized isolated beta-subunit were also performed. The mature alpha- and beta-subunits contain 1016 and 302 amino acid residues, respectively. Structural data on the peptides from extramembrane regions of the alpha-subunit and on glycopeptides of the beta-subunit underlie a model for the transmembrane arrangement of Na+,K+-ATPase polypeptide chains.

[Primary structure of the alpha subunit of Na+,K+-ATPase. I. Analysis of hydrophilic fragments of the polypeptide chain]. / Pervichnaia struktura alpha-sub''edinitsy Na+,K+-ATP-azy. I. Analiz gidrofil'nykh fragmentov polipeptidnoi tsepi.

The selective tryptic digestion of the native membrane-bound enzyme was carried out under conditions that provide the extensive hydrolysis of hydrophilic regions of the alpha-subunit into small fragments and allow to preserve the integrity of the beta-subunit. Twenty-seven water-soluble peptides comprising approximately 40% of the total polypeptide chain were isolated by HPLC and their complete or partial amino acid sequence was determined. It led to general outline of the structural organisation of the alpha-subunit hydrophilic regions exposed from membrane. The information thus obtained was used in synthesis of specific oligonucleotide probes.

[Primary structure of the OSCP protein that confers sensitivity to oligomycin on the mitochondrial H+-ATPase complex. I. Tryptic and cyanogen bromide peptides]. / Pervichnaia struktura OSCP--belka, pridaiushchego mitokhondrial'nomu H+-ATP-aznomu kompleksu chuvstvitel'nost' k oligoitsinu. I. Tripticheskie i bromtsianovye peptidy.

Trypsin and cyanogen bromide were used for cleavage of the OSCP preparations. The peptide mixtures thus formed were separated into individual components by a combination of various chromatographic procedures: gel filtration, ion exchange and paper chromatography, as well as reversed-phase HPLC. As a result, 31 tryptic peptides and 9 out of 10 possible cyanogen bromide peptides were isolated. Determination of the amino acid sequences of these peptide allowed the alignment of cyanogen bromide fragments in the polypeptide chain that shed light on the "architecture" of the protein molecule as a whole. It also afforded the overlappings for tryptic peptides, 16 in the N-terminal and 8 in the C-terminal portions of the molecule.

Oligomycin sensitivity-conferring protein (OSCP) of beef heart mitochondria. Internal sequence homology and structural relationship with other proteins.

Structural analysis of oligomycin sensitivity-conferring protein (OSCP) revealed repeating sequences (residues 1-89, 105-190) suggesting an evolution of the protein by gene duplication. In addition to the reported homology with the delta-subunit of Escherichia coli F1ATPase, OSCP also shows a certain homology with the b-subunit of E. coli F0 and the ADP/ATP carrier of mitochondria.

Amino acid sequence of the oligomycin sensitivity-conferring protein (OSCP) of beef-heart mitochondria and its homology with the delta-subunit of the F1-ATPase of Escherichia coli.

The complete amino acid sequence of the oligomycin sensitivity-conferring protein (OSCP) of beef-heart mitochondria is reported. The protein contains 190 amino acids and has a molecular mass of 20 967. Its structure is characterized by a concentration of charged amino acids in the two terminal segments (N 1-77 and C 128-190) of the protein, whereas its central region is more hydrophobic. The earlier reported homology of the protein with the delta-subunit of E. coli F1, based on the terminal amino acid sequences of OSCP, is further substantiated.