PubMed Health⌕ Search

Biomedical subjects

T S Bondar'

Publications and source records attributed to T S Bondar'.

5 recordsLinked to original sources
PubMed2000

[New rare cutting restriction endonuclease SmII from Streptococcus milleri recognises 5'-ATTTAAAT-3'].

New restriction endonuclease (restrictase) Smil of type II was detected in the bacterial strain Streptococcus milleri. Cellular lysate enzyme cut T7 and adenovirus-2 DNAs at site 5'-ATTT decreases AAAT-3' but not lambda DNA which does not contain this sequence. Intense aeration inhibited the growth of S. milleri. The content of restrictase in the cells was the greatest during the logarithmic growth phase. A total of 20,000 units of Smil were isolated from 4 g of cells by cellular extract fractionation with ammonium sulfate and subsequent chromatography on columns with Bio Gel A 0.5 m, heparin agarose, and phosphocellulose. Purified enzyme cut the synthetic oligonucleotide duplex in the center of the recognized site 5'-ATTT decreases AAAT-3'. Smil restrictase is a true isoschisomer of rare-cutting Swal enzyme. Smil belongs to a small group of enzymes which recognize octanucleotide sites and can be used for large-block fragmentation of DNA. Comparison of specificities of rare-cutting and other restrictases suggests that the enzymes recognizing octanucleotides can evolutionally originate from enzymes recognizing both hexanucleotides and tetranucleotides.

Adenoviridae↗
PubMed1999

[The clinico-laboratory criteria of brain death in neurosurgical patients].

With the purpose of developing scientifically substantiated criteria for brain death complex of clinical and physiological, biochemical, physicochemical, and morphological studies was initiated in 55 patients in a critical state because of a dangerous craniocerebral injury, tumours, and vascular affections of the brain. Generalized in the paper are well-known parameters characterizing irreversibility of changes. The following items are to be regarded as the principal criteria for brain death at the present stage of development of medicine: death of truncus cerebri and irreversibility of metabolic disturbances in brain activity.

Biomarkers↗
PubMed1997

[Expression of the gene for vaccinia virus 36K nonstructural protein in Escherichia coli and study of the protective properties of expression products].

The nonstructural 36K protein of vaccinia virus (VV) mapped in HindIII-P and HindIII-J fragments of VV strain L-IVP has been expressed in E. coli as a fusion protein. The products of 36K gene preserved the antigen homology with the native protein 36K and the capacity to bind specific immunoglobulins of rabbit antiVV serum. The protective properties of 36K gene products and their joint effect with the immunodominant protein 35K were investigated. The non-structural 36K gene products showed no protective activity, but increased the production of specific antibodies in mice immunized with a mixture of both protein preparations, this increase being compatible with that observed after immunization with the inactivated virus preparations.

Animals↗
PubMedDate not supplied

[Complementary interaction of multialkylated polyribonucleotides].

Effect of modification of polyinosinic acid (poly(I)) by alkylating agent 4-N,N-bis (beta-chloroethyl) aminobenzaldedehyde on its complementary interaction with polycytidylic acid (poly(C)) was investigated. The data demonstrate that when no more than 10% of inosine residues are modified poly(I) still retains its capacity to form complementary complex with poly (C) this capacity disappears after modification of 11--13% of inosine residues. However when more than 3,5% of inosine residues were modified the poly(I). .poly(C) complex became sensitive to RNAse T1 and its Tm decreases, indicating that single-stranded regions (loops) are formed under these conditions. The data suggest that modified polynucleotides carrying alkylating groups on their surface can be applied for the directed action on the complementary regions of the genome.

Alkylation↗