PubMed Health⌕ Search

Biomedical subjects

M A Aĭtkhozhin

Publications and source records attributed to M A Aĭtkhozhin.

7 recordsLinked to original sources

[Nucleotide sequence organization of nuclear DNA of wheat embryos].

The kinetic component composition of wheat embryo nuclear DNA was studied. It was shown that 32% of the genome consist of highly repetitive sequences. Intermediate repetitive sequences with repetitive frequency 1300 per genome constitute the bulk (52%) of the wheat embryo nuclear genome. The unique sequences constitute 12% of wheat embryo DNA. The individual families of intermediate repetitive and unique sequences were isolated; their reassociation kinetics were investigated and their kinetic complexity and repetition frequency were evaluated. Intermediate repetitive sequences 600-800 nucleotides in length were interspersed with unique sequences 800-1000 nucleotides long in the nuclear genome of wheat embryos. The linear relationship between the fragment length and the increasing amount of the zero-time binding DNA implies that 4% of the wheat embryos genome consists of palindromic sequences, which are clustered into groups.

Base Composition↗

[Poly A-protein complexes in polyribosomes of sprouting wheat embryos].

A purified polyribosome preparation has been isolated from sprouting wheat embryos. After treatment of the polyribosomes with pancreatic RNase the poly-A-sequences are found in the fractions sedimenting in the region of 8--14 S. The ability of 8--14 S poly-A-containing complexes to bind to the membrane filters at high ionic strength and their sensitivity to pronase indicate that in sprouting wheat embryo polyribosomes the poly-A-sequences occur as poly-A-protein complexes.

Base Sequence↗

[Proteins of polyribosome-bound informosome of germinating wheat embryos].

Proteins of polyribosome-bound informosomes of germinating wheat embryos were studied by electrophoresis in polyacrylamide gel in presence of sodium dodecyl sulfate. liberation of informosomal proteins was achieved by mild ribonuclease treatment of polyribosomes. It was shown, that proteins of informosomes associated with polyribosomes contain polypeptides with molecular weights of 86 000, 75 000, 72 000, 66 000, 52 000 and 34 000. The milecular weights of two most prominent proteins were 86 000 and 52 000. The treatment of polyribosomes with 0.5 M KCl resulted in the loss of large part of informosomal proteins, which are revealed in the KCl-wash.

Molecular Weight↗

[Poly(A)-containing RNA from germinating wheat embryos].

Rapidly labelled mRNAs were isolated from informosomes and polyribosomes of imbibed wheat embryos. The distribution of poly(A) sequences in these fractions were studied by poly(U) Sepharose chromatography. It was shown that informosomes contain 11% polyadenylated mRNA while polyribosomes--38%. This fact suggests the important role of poly(A) sequences for translation of mRNA.

Base Sequence↗

[Release of informosomes from isolated nuclei of wheat embryos in an in vitro system].

The properties of the informosomes released from isolated nuclei of wheat embryos were studied in an in vitro system. The release of the informosomes from isolated nuclei of wheat embryos labelled with [3H]uridine is stimulated by exogeneous ATP. Optimal conditions for informosomes release from nuclei were determined. The particles obtained have heterogeneous sedimentation coefficients in sucrose gradient ranging from 10 to 60S. The particles are sensitive to low concentrations of RNase. Buoyant density in CsCl is 1.40-1.43 g/cm3. RNA extracted from particles is characterized by heterogeneous distribution in sucrose gradient between 4 and 20S. The informosomes contain two main peptides with molecular mass 36 000 and 51 000 and a number of minor peptides.

Cell Fractionation↗