[Prediction of peptide retention volumes in the gradient reversed phase HPLC].

A method of computation of retention volumes of linear peptides of known composition that contain no more than 25 amino acids in gradient reversed phase HPLC was developed. The method is suitable for various acetonitrile gradient profiles. The calculations were carried out on the basis of a statistical model, the parameters of which were experimental dependences of the retention of individual amino acids on acetonitrile concentration. The method developed was used to predict the chromatographic behavior of 34 peptides in four different acetonitrile gradients. The correlation coefficients between the predicted and experimental retention volumes were more than 0.9, and the average relative error of prediction was less than 15%. The English version of the paper: Russiatn .lournal of Bioorganic Chemistry, 2008, vol. 34, no. 2; see also http://www.maik.ru.

[Prediction of retention volumes and UV spectra of peptides in reversed phase HPLC].

A method for calculating retention volumes of linear peptides with known primary structures and the values of their UV absorption at chosen wavelengths in reversed phase HPLC are described. These parameters are calculated for every peptide on the basis of the contributions of its amino acid residues determining its degree of retention and its UV spectrum. The contribution values are experimentally found from chromatograms of the free amino acids obtained by multiwavelength photometric detection under the conditions of the peptide chromatography. Thirty peptides have been chromatographed for the evaluation of the proposed method, and the correlation coefficients between the calculated and the experimental retention volumes have been found to be 0.95.

New potentialities of HPLC in pharmacopoeian analysis.

Modern status of pharmacopoeian HPLC analysis and its main shortcomings are discussed. The philosophy "special analytical method for each substance" has to be revised, and as an alternative, a principle of creation of universal methods realized by means of HPLC analyzers is proposed. A prototype of such analyzer is described. The device was designed on the basis of a Milichrome A-02 gradient chromatograph with spectrophotometric detector and reverse phase column.

[Degradation of bis(2-ethylhexyl)phthalate by microorganisms of water and sediments of the Selenga river and Baikal Lake under experimental conditions]. / Degradatsiia bis-(2-étilgeksil)ftalata mikroorganizmami vody i donnykh osadkov r. Selengi i oz. Baikal v usloviiakh model'nogo éksperimenta.

Degradation of bis-(2-ethylhexyl)phthalate (BEHP) by microbial associations of water and bottom sediments of the Selenga River and Lake Baikal and by pure cultures of microbial species belonging to various taxa isolated from the sediments under discussion has been studied. It has been shown that intense biological degradation occurs in both water and sediments. The degrees of conversion in experimental closed systems on minimal media are 46 and 24%, respectively. The most active of the organisms studied is a Micromironospora actinomycete. It degraded BEHP by 36% of its initial concentration. Spore-forming bacteria and microorganisms of the genus Pseudomonas were less active (17-23% and 7-11%).

[Amino acid sequence of myoglobin from seals from Lake Baikal]. / Aminokislotnaia posledovatel'nost' mioglobina baikal'skoi nerpy.

The primary structure of myoglobin of the seal of Lake Baikal (East Siberia) Phoca siberica, determined by sequencing the whole protein and peptides obtained by the cyanogen bromide or proteinase cleavage and separated by the microcolumn liquid chromatography, was found to be identical to the primary structures of myoglobins of the harbour seal Phoca vitulina largha and the grey seal Halehoerus gryphus. It suggests that these species separated from a common ancestor less than seven million years ago.

Determination and characterization of chloroguaiacol conjugates in fish bile by HPLC.

In this study a small-scale technique for direct analysis of metabolic conjugates of 4,5,6-trichloro- (CG-3) and tetrachloroguaiacols (CG-4) in fish bile by RP-HPLC is presented. Only one metabolite, glucuronic acid conjugate, was demonstrated in two Lake Baikal fishes (Leuciscus leuciscus baikalensis and Cottus kessleri) exposed to CG-3 or CG-4 at 6 degrees C for 1-2 days. In Leuciscus the ratio between free CG-4 in the ambient water and conjugated CG-4 in the bile averaged 264,000. Intraperitoneal injections of tetrachloroveratrol (CV-4) into Thymallus arcticus baikalensis did not reveal any traces of free CV-4 or CG-4 glucuronide in the bile in 2 days at 5 degrees C. We therefore suggest that CV-4 was not demethylated and subsequently conjugated with glucuronic acid in the liver of this fish species.

[Multiplicity of affinity modification of RNAse during its alkylation with a reactive analog of 5-deoxyribonucleotide]. / Mnozhestvennost' affinnoi modifikatsii RNKazy pri alkilirovanii ee reaktsionnosposobnym analogom 5'-dezoksiribonukleotida.

The interaction of pancreatic RNase with 5'-deoxyribodinucleotide alkylating derivative, 4-(N-2-chloroethyl-N-methylamino)benzylamide of d(pTpA) d[(ClRCH2NH)pTpA], was studied. The unreactive oxyanalogue d[(HORCH2NH)pTpA] was shown to act as competitive inhibitor of cCMP hydrolysis by RNase. d[(ClRCH2NH)pTpA] irreversibly inactivated RNase. A protective effect was exerted by d(pTpA) and d[(HORCH2NH)pTpA]. The modification, although having an affinity character, was not accompanied by total inactivation of the enzyme. It was supposed that covalent bonding between the reagent and enzyme induced the dinucleotide displacement from the recognition site. The formation of four RNase monolabeled forms retaining the activity in the hydrolysis of cCMP and poly(U) was demonstrated.

Dynamic aspects of affinity labelling as revealed by alkylation and phosphorylation of pancreatic ribonuclease with reactive deoxyribodinucleotide derivatives.

Affinity labelling of pancreatic RNase with 4-(N-2-chloroethyl-N-methylamino)benzylamide and (N----P) N-methylimidazolide of d(pTpA) results in the formation of monomodified enzyme derivatives retaining partially enzymatic activity. These data together with some cases described in the literature are considered as suggesting the dynamic nature of the enzyme-reagent complex represented by a set of states differing in the probability of intra-complex reaction. In particular, modification may proceed in a low probability state with an especially favorable mutual orientation of reagent and some protein residue remote from the active site of the enzyme resulting in the removal of the covalently attached reagent moiety from the active center.

[Amino acid sequence of various tryptic peptides of the envelope protein of the tick-borne encephalitis virus]. / Posledovatel'nost' aminokislot nekotorykh tripticheskikh peptidov belka obolochki virusa kleshchevogo éntsefalita.

Protein E of the tick-borne encephalitis virus (TBEV) (strain Sofin) was treated with purified trypsin in 1% Triton X-100, and the peptides thus obtained were separated by micro-column reversed-phase chromatography. Four of the purified peptides were sequenced, their structures being in accordance with the nucleotide sequence of the viral protein E gene. Amino acid sequences of peptides deduced from the cDNA primary structure are: Ser-Val-Leu-Ile-Pro-Ser-His-Ala-Gln-Gly-Asp-Leu-Thr-Gly-Arg (N-terminal peptide of protein E); Thr-Glu-Gly-Ala-Gln-Asn-Trp-Asn-Ala-Glu-Arg: Trp-Leu-Glu-Gly-Asp-Ser-Leu-Arg; Leu-Val-Glu-Phe-Gly-Ala-Pro-His-Ala-Val-Lys.

[Isolation of brain monoamines using high-performance reversed-phase chromatography]. / Vydelenie monaminov mozga s pomoshch'iu vysokoéffektivnoi khromatografii na obrashchennoi faze.

The content of monoamines, their precursors and metabolites was measured in brain specimens weighing several milligram by ion-pair high performance liquid chromatography on reversed phase microcolumns together with electrochemical detection. The properties of different sorbents are compared and the choice of a mobile phase is discussed. The technique of column packing and preparation of brain samples are described.