PubMed Health⌕ Search

Biomedical subjects

S V Zenin

Publications and source records attributed to S V Zenin.

12 recordsLinked to original sources
PubMed1977

Nuclear magnetic resonance of nucleotide-amidates. Investigation of the secondary structure of methylester of deoxyadenylyl-(5'-3')-deoxyadenylyl-(5' leads to N)-L-phenylalanine.

The secondary structure of methyl ester of deoxyadenylyl- - (5' - 3') - deoxyadenylyl - (5' leads to N) - L-phenylalanine / L- PheOMe - d(pApA)/ was investigated using proton magnetic resonance. The folded conformation stabilized by hydrophobic interactions in aqueous solution was shown for this compound. The investigation of the chemical shifts of aromatic protons of L- PheoOMe - d(pApA) permitted us to construct the conformational model of this compound.

Deoxyadenine Nucleotides↗
PubMed1975

Dependence of noncovalent interactions of benzene and adenine rings on distance between them in adenylyl-(5' yields N)-omega-arylalkylamines.

A series of adenylyl-(5' yields N)-omega-arylalkylamines, containing from one to six methylene groups in the amino component, was studied by methods of nuclear magnetic resonance and circular dichroism. It was shown that independently of the length of the aliphatic chain of the amine convergence of the adenine and benzene rings and a hydrophobic interaction between them occur. The plane of the benzene ring is inclined toward the adenine ring, which has an anticonformation relative to the ribose. The structure of the intramolecular complex and the energy of the interaction of the aromatic systems of the amine and nucleotide depend on the number of methylene groups in the amino component. Maximum interaction occurs in the presence of two methylene groups; weakening of the interaction occurs with an increase in the chain to four links, which does not change upon further lengthening of the chain. The conformation of adenylyl-(5' yields N)-benzylamine differs from the structure of the other compounds of the series investigated.

Adenine↗
PubMedDate not supplied

[Intermolecular interaction of adenosine-5'-phosphate with phenylalanine and tryptophan by nuclear magnetic resonance].

Equilibrium constants (K) of the complex formation of adenosine-5'-phosphate with phenylalanine (27 l/mol) and tryptophan (67 l/mol) in water (D2O, pD 9.9) have been determined. The comparison of the equilibrium constant values allowed to find the sequence of probabilities of the approach of aromatic amino acids to adenosine-5'-phosphate (tryptophan greater than tyrosine greater than phenylalanine). It has been shown that the dependence of lg K on l/T in the system phenylalanine-adenosine-5'-phosphate is non-linear. The ranges of the positive values of enthalpy (deltaH) and entropy (deltaS) changes of the complex phenylalanine-adenosine-5'-phosphate formation in the temperature interval 28-65 degrees have been found (deltaH = 0.2-1.5 kcal/mol, delta S = 14-50 e.u.). The conclusion about the hydrophobic interaction of aromatic cycles of nucleotide and amino acids has been deduced from the received data.

Adenosine Monophosphate↗
PubMedDate not supplied

[The secondary structure of nucleotidyl-(5' bound to N)-amino acids containing different heterocyclic bases and amino acids].

Nucleotidyl-(5' leads to N)-amino acids containing different heterocycle bases: adenine, guanine, hypoxanthine, cytosine, uracyl, and aromatic amino acids: phenylalanine, tyrosine and tryptophan, have been investigated by proton magnetic resonance and circular dichroism. For all the compounds studied folded conformation have been shown stabilized by hydrophobic interaction in aqueous solution. The comparison of the results of the studied nucleotidyl-(5' leads to N)-amino acids unable us to build four secondary structure types in these very compounds. Phenylalanine and tyrosine derivatives of purine nucleotides can be regarded as the first type, tryptophan derivatives of purine nucleotides as the second type, phenylalanine and tyrosine derivatives of pyrimidine nucleotides as the third type and tryptophan derivatives of pyrimidine nucleotides as the fourth type. For each group of these compounds conformational models have been built. In all these compounds the anti-conformation has been proved to exist.

Amino Acids↗
PubMedDate not supplied

[Nuclear magnetic resonance of nucleotidamides. Structure of the intramolecular complex of the methyl ester of deoxyadenylyl-(5'-3')-deoxyadenylyl-(5'--N)-L-phenylalanine].

The secondary structure of methyl ester of deoxyadenylyl-(5'--3')-deoxyadenylyl-(5' leads to N)-L-phenylalanine [l-pheOMe-d (pApA)] has been investigated by proton magnetic resonance. For this compound folded conformation stabilized by hydrophobic interaction in aqueous solution has been shown; and the anti-anti-conformation has been proved to exist. The investigation of chemical shifts of aromatic protons in L-PheOMe-d (pApA) has permitted us to build the conformation model of this compound.

Chemical Phenomena↗
PubMedDate not supplied

[The secondary structure of amides of adenylic acid containing D- and L-aromatic amino acids].

Adenylyl-(5'leads to N)-amino acids containing as amino components, methyl esters of D-, L- and DL-phenylalanine, D-, L- and DL-tyrosine, and D-, L- and DL-tryptophan have been investigated by proton magnetic resonance (PMR) spectroscopy and circular dichroism (CD). The temperature and pD dependences of proton chemical shifts of these compounds have been studied. These data, together with the magnitudes of the upfield chemical shifts of the PMR signals of adenine and aromatic amino acids residues in adenylyl-(5'leads to N)-amino acids, have enabled us to construct conformational models of these compounds. The proposed conformation has been substantiated by the CD results. It is shown that in adenylyl-(5'leads to N)-amino acids the planes of adenine and amino acid aromatic moieties are roughly parallel. The aromatic rings of phenylalanine and tyrosine are localized approximately above the centre of adenine. In adenylyl-(5'leads to N)-D, -(L)-tryptophan, the six-membered rings of the indole overlaps the five-membraned ring of adenine indole partially overlaps the six-membered ring of adenine. A difference in the non-covalent interactions of D- and L-amino acids with nucleotides has been revealed. The mutual localization of the aromatic systems of AMP and the amino acids and also the positions of -OCH3 group with respect to the centre of the amino acid aromatic moiety differs in the series of the studied nucleotide derivatives of D- and L-amino acids.

Adenosine Monophosphate↗