Search PubMed⌕ Search

Biomedical subjects

V A Otroshchenko

Publications and source records attributed to V A Otroshchenko.

16 recordsLinked to original sources
PubMed1997

The emergence of the non-cellular phase of life on the fine-grained clayish particles of the early Earth's regolith.

A scenario of the origin of the very first ribonucleoproteinoid virus-like complexes, which is based on their synthesis in the interlaminar spaces of clayish grain regolith of the primitive Earth, about 4 billion years ago when water in the form of liquid drops first appeared. The proposed model explains the origin of chirality of modern biopolymers as a result of preferential adsorption of biomonomers on such grains.

Adsorption↗
PubMed1992

Polycondensation reactions of certain biologically essential molecules on mineral surfaces.

Methods of detecting extraterrestrial forms of organic matter should take into account the results of research in the effects of irradiation on the synthesis of biopolymers. Processes occurring on clay mineral surfaces and on the surfaces of minerals of different kinds are illustrated and the possible role of clays in prebiological evolution is discussed.

Aluminum Silicates↗
PubMed1987

Catalytic activity of the nucleic acid component of the 1,4-alpha-glucan branching enzyme from rabbit muscles.

2.5 S RNA, the nucleic acid component of the 1,4-alpha-D-glucan: 1,4-alpha-D-glucan 6-alpha-(1,4-alpha-glucano)-transferase from rabbit muscles, devoid of any protein, catalyses the branching reaction, as does the holoenzyme. The conclusion is drawn that 2.5 S RNA is a ribozyme. To get an insight into the significance of different parts of the molecule for the catalytic activity of 2.5 S RNA, a large fragment isolated from its partial RNAase A digest was investigated. This fragment which proved to be the middle part of polyribonucleotide chain containing all modified nucleotides exerts some catalytic activity, too.

1,4-alpha-Glucan Branching Enzyme↗
PubMed1986

Abiogenic synthesis of oligonucleotides on kaolinite under the action of ultraviolet radiation.

The present work deals with the processes involved in the abiogenic polycondensation of nucleotides adsorbed on the clay mineral kaolinite under the action of ultraviolet (UV) radiation. The dependence of the yield of synthesis products on irradiation dose was studied. The maximum yield corresponds to a 6-h exposure. The newly synthesized substances were analyzed by ion-exchange chromatography. Some fractions were studied for the type of bonds they contained by venom phosphodiesterase and RNase T2 enzymatic hydrolysis. It was determined that some of the products synthesized by exposure of AMP adsorbed on the surface of clay particles to UV radiation may be looked upon as oligonucleotides in which some fragments have 2'-5'-bonded and others 3'-5'-bonded nucleotides.

Adenosine Monophosphate↗
PubMed1977

The role of mineral surfaces in the origin of life.

Adsorption of nucleoside phosphates on the surfaces of volcanic rocks has been studied. Differences in the absorption of some nucleoside phosphates on the surface of basalt cinder have been found. Differences in the adsorption of similar molecules on different mineral surfaces have also been shown. Different adsorptive capacities may have served as a mechanism for the selection of organic molecules during prebiotic evolution.

Adenosine Diphosphate↗
PubMedDate not supplied

[The simultaneous synthesis of peptides and oligonucleotides on kaolinite with the participation of aminoacyladenylates].

A simultaneous synthesis of peptides (2-5 residues) and oligonucleotides (3-9 residues) has been carried out on caolinite matrix using amino acids and aminoacyladenylates as substrates. The rate of oligomer synthesis on mineral surface is higher than that in solution. The mechanism of synthesis has been described. The data has been discussed in connection with abiogenesis of two major types of biopolymers, proteins and nucleic acids.

Adenosine Monophosphate↗