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Biomedical subjects

K Oda

Publications and source records attributed to K Oda.

At least 631 records · Page 35Linked to original sources
PubMed1978

Multiple forms of albumin and their conversion from pro-type to serum-type in rat liver in vivo.

Purified rat serum albumin was resolved into five forms by polyacrylamide gel isoelectric focusing, while albumin isolated from the subcellular fractions of rat liver consisted of those of serum albumin and four additional forms. This latter four forms were identified as proalbumin, since they were converted to those of serum albumin by limited proteolysis with trypsin. This method was applied to the determination of the conversion site of proalbumin in the liver, revealing that substantial conversion of proalbumin occurs in the Golgi cisternae as well as in the secretory vesicles.

Animals↗
PubMed1978

Detection of unique tRNA species in tumor tissues by Escherichia coli guanine insertion enzyme.

The guanine insertion enzyme from Escherichia coli catalyzes exchange of guanine located at the first position of the anticodon of tRNA with radioactive guanine (N. Okada and S. Nishimura, unpublished data). tRNA isolated from various tumors, including slowly growing Morris hepatoma 7794A, incorporated considerable guanine with E. coli guanine insertion enzyme, whereas tRNA isolated from all normal tissues so far tested, except regenerating rat liver, incorporated scarcely any. In the rat ascites hepatoma AH7974, the guanine was mostly incorporated into minor isoaccepting species of tRNAAsp that contained the guanine residue instead of Q base in the first position of the anticodon. This is a sensitive and easy method for identifying unique tRNA species in tumor tissues.

Animals↗
PubMed1978

Phosphorylation of chromatin- and ribosome-associated proteins in cells transformed by adenovirus, murine sarcoma virus, and methylcholanthrene.

Endogenous protein phosphorylation in chromatin and ribosomes of monkey, mouse, and rat cells transformed by DNA, RNA tumor viruses, and a chemical carcinogen revealed the association of a protein of approximately 90,000 daltons (90K), which is highly phosphorylated in vitro. Peptide map analysis showed that the 90K proteins associated with these organelles of various transformed cells are similar irrespective of the species of cells and transforming agents. This species of protein could not be detected, or was scarcely detected, by phosphorylation in chromatin and ribosomes of untransformed cells and in revertants of transformed cells. These results suggest that the alteration in the pattern of endogenous protein phosphorylation in these organelles is closely related to the transformed state of cells.

Adenoviruses, Human↗
PubMed1977

Acceptor activity of subcellular membranes for two terminal sugars, galactose and sialic acid.

The acceptor activities of subcellular membrane preparations for the terminal sugars, galactose and sialic acid, were compared using a Golgi fraction purified from rat liver as an exogenous emzymes source for sugar transfer. Data are presented which strongly suggest that completion of carbohydrate chains of membrane glycoproteins and glycolipids occurs in the Golgi apparatus. Significant differences of acceptability of galactose and sialic acid were found between plasma membranes of rat liver and hepatoma cells (AH-130), indicating "incompleteness" of sugar chains in the latter.

Animals↗
PubMed1977

Simian virus 40 gene A regulates the association between a highly phosphorylated protein and chromatin and ribosomes in simian virus 40-transformed cells.

The species of proteins associated with chromatin and ribosomes of simian virus 40 (SV40)-transformed and untransformed monkey, mouse, and rat cells have been compared by sodium dodecyl sulfate-polyacrylamide gel electrophoresis after phosphorylation of these proteins either in vivo or in vitro. In vitro phosphorylation was carried out by protein kinase associated with these organelles and [gamma-(32) P]ATP as the phosphoryl donor. The reaction products contained both phosphoserine and phosphothreonine in approximately equal amounts. The electrophoretic analysis of the phosphorylated proteins revealed that the highly phosphorylated protein with a molecular weight of approximately 90,000 (90K protein) was associated with chromatin and ribosomes from transformed cells but not from untransformed cells. The 90K protein could be extracted from chromatin and ribosomes with 0.5 to 1.0 M NaCl or KCl. The 90K protein was still associated with the runoff ribosomes prepared by the puromycin reaction of the post-mitochondrial supernatant in the protein-synthesizing system. In vitro phosphorylation of chromatin and ribosomes from SV40 tsA-transformed mouse and rat cells indicated that the amounts of 90K protein associated with these organelles decreased greatly when the cells were cultivated at the restrictive temperature. A similar temperature-dependent decrease in the amount of (32)P-labeled 90K protein was observed in nonhistone chromosomal and ribosome-associated protein fractions prepared from SV40 tsA-transformed cells labeled with [(3)H]leucine and [(32)P]orthophosphate in vivo. In vitro phosphorylated 90K protein in nonhistone chromosomal and ribosome-associated proteins extracted with high salt was not immunoprecipitated with anti-SV40 T sera.

Adenosine Triphosphate↗
PubMed1977

An improved method for the purification of rat serum albumin: removal of contaminants by concanavalin A-Sepharose.

Minor contaminants occasionally found in conventionally prepared rat serum albumin were easily and completely removed by concanavalin A-Sepharose chromatography. The unadsorbed fraction from a concanavalin A-Sepharose column contained albumin which was homogeneous on polyacrylamide gel electrophoresis. The recovery of albumin form rat serum was approximately 30%. Approximately 2% of the added protein obtained as an albumin peak in DEAE-cellulose chromatography was adsorbed on and eluted with alpha-methyl-D-glucoside from the concanavalin A-Sepharose column, and resolved into three components by gel electrophoresis. There was one major glycoprotein, possibly alpha 1-antitrypsin, and two minor proteins one of which was albumin.

Animals↗