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T Takagi

Publications and source records attributed to T Takagi.

At least 955 records · Page 53Linked to original sources
PubMed1977

Amino acid sequence studies on the alpha chain of human fibrinogen. Characterization of 11 cyanogen bromide fragments.

The alpha chain of human fibrinogen consists of 600 +/- 25 amino acid residues, 10-11 of which are methionines. In this regard, we have identified and characterized 11 cyanogen bromide peptide fragments of 2, 3, 26, 28, 28, 37, 51, 56, 60 +/- 5, 64 +/- 5, and 260 +/- 20 residues, respectively. The sequences of five of these and a portion of a sixth have been reported previously. We now report the complete amino acid sequences of another of these fragments (56 residues), partial sequences for four others, and a preliminary characterization of the largest fragment. In a companion study (Doolittle, R. F., Cassman, K. G., Cottrell, B. A., Friezner, S. J., and Takagi, T. (1977), Biochemistry 16 (following paper in this issue)), we have obtained key overlap sequences from plasmic digests of fibrinogen which allow all but one of these cyanogen bromide peptides to be arranged in order. The sequences of some of these newly reported fragments have revealed an internal homology in the alpha chain, as well as structural similarities to the corresponding portions of the beta and gamma chains.

Amino Acid Sequence↗
PubMed1977

Amino acid sequence studies on the alpha chain of human fibrinogen. Covalent structure of the alpha-chain portion of fragment D.

The alpha-chain portion of fragment D has been purified from an exhaustive plasmic digest of human fibrinogen. The major polypeptide species has 91 amino acid residues, although a small amount of a 97-residue chain representing an earlier digestion stage remains. The amino acid sequence of the first 44 residues was determined by stepwise degradation with an automatic solid-phase sequencer. Another large stretch of sequence was revealed by the finding that the alpha chain of fragment D overlaps the cyanogen bromide fragments alphaCNIVA and alphaCNIII (Doolittle, R. F. Cassman, K. G., Cottrell, B. A., Friezner, S. J. Hucko, J. T., and Takagi, T. (1977), Biochemistry 16 (preceding paper in this issue)). The automatic sequencer results were confirmed and extended by the isolation and characterization of 18 of 19 expected tryptic peptides from the fragment D alpha chain. As a result, almost the entire sequence has been obtained. The overlap with key cyanogen bromide fragments has also allowed us to propose an order for the first 198 residues of the fibrinogen alpha chain. A striking homology with the gamma chain and beta chain is apparent which has interesting structural implications.

Amino Acid Sequence↗
PubMed1977

Gas chromatographic separation of cholesteryl esters of fatty acids of different degrees of unsaturation.

Cholesteryl esters prepared from the fatty acid methyl esters of linseed oil, pig liver lipids, and Japanese anchory oil have been separated on the basis of their chain lengths and number of double bonds by gas liquid chromatography on a cyanosiloxane SILAR 10C column. The equivalent chain lengths of cholesteryl esters having acyl groups with 14-22 carbons and 0-6 double bonds are presented. A significant influence of the column temperature on the equivalent chain lengths of the polyenoic fatty acid cholesteryl esters has been found. Separation of the cholestanyl and epicholestanyl esters of linseed oil fatty acids, respectively, under the same conditions is also described.

Animals↗
PubMed1977

Pigmented cosmetic dermatitis and coal tar dyes.

Patch tests and photopatch tests with various cosmetics, coal tar dyes, perfumes, lanolin preparations and parabens-mix were performed in 53 patients with pigmented cosmetic dermatitis similar in clinical appearance to Riehl's melanosis. The results showed that coal tar dyes, particularly brilliant lake red R, were closely related to the cause of the disease. In patch testing and photopatch testing with coal tar dyes, the incidence of positive responses to the brilliant lake red R was found to be significantly higher than that to the other coal tar colors (22/38 = 57.9%). The relevance of ultraviolet light to the disease was found to be much less than the ratio expected (14/47 = 29.8%). A high incidence of positive responses to fragrances was also found, but it is considered to play a secondary role in the etiology of the disease.

Coal Tar↗
PubMed1977

L-Histidine production by histidase-less regulatory mutants of Serratia marcescens constructed by transduction.

2-Methylhistidine (2MH) and 1,2,4-triazole-3-alanine (TRA) inhibited the growth of Serratia marcescens. These inhibitory effects were counteracted by L-histidine. Enzymatic studies showed that 2MH acts as a false feedback inhibitor and TRA acts as both a false feedback inhibitor and a repressor. Mutants resistant to each analog were isolated from a histidase-less mutant, because the wild-type strain possesses a potent histidase activity. 2MH-resistant mutants had a feedback-insensitive phosphoribosyltransferase, but they produced only small amounts of L-histidine. TRA-resistant mutants were divided into two types according to their histidine productivity. A mutant of one type produced about 8 mg of L-histidine per ml and had about a 10-fold increase in the enzyme levels of histidine biosynthesis. Moreover, this mutant had a partially feedback-insensitive phosphoribosyltransferase. A mutant of the second type produced only a small amount of L-histidine and had only derepressed enzyme levels. Accordingly, strains possessing the genetic alterations in both 2MH- and TRA-resistant mutants were constructed by PS20-mediated transduction. They had both feedback-insensitive phosphoribosyltransferase and derepressed enzyme levels. The representative strain HT-2604 produced about 17 mg of L-histidine per ml.

Drug Resistance, Microbial↗
PubMed1977

Increase in arginine and citrulline production by 6-azauracil-resistant mutants of Bacillus subtilis.

In the arginine producer AHr-5, an L-arginine hydroxamate-resistant mutant of Bacillus subtilis, accumulation of N8-acetyl-L-ornithine increased as the level of L-arginine accumulation increased in the medium containing L-glutamic acid. Ornithine carbamoyltransferase of this strain was genetically derepressed. These results suggested that carbamoylphosphate might be deficient in vivo. With the intention to increase endogenous carbamoylphosphate, pyrimidine analogs inhibiting growth were selected and the mutants resistant to these compounds were derived from the AHr-5 mutant. Of the resistant mutants derived, the 6-azauracil-resistant mutant AAr-9 produced 28 mg of L-arginine per ml, which corresponded to more than twofold the amount produced by the parent strain. Derivation of an arginine-requiring mutant from the double-resistant mutant AAr-9 provides a new advantageous method for the production of L-citrulline. The increase in arginine and citrulline production is discussed.

Arginine↗
PubMed1977

Mobilization of cellular calcium and contraction-relaxation of vascular smooth muscle.

In order to clarify the Ca2+ mediated regulatory mechanism of vascular smooth muscle, the correlation between Ca2+ movements in the cell and mechanical response was investigated using isolated rat aorta and bovine basilar artery. K+ induced contraction of vascular smooth muscle required Ca2+ in the medium, and the contraction was always associated with a large increase in Ca2+ influx. In the absence of external Ca2+, norepinephrine (NE) or serotonin (5HT) induced rapid contraction of the aorta and basilar artery, respectively. Caffeine (20 mM) also induced tension in the absence of Ca2+. The results obtained in these experiments suggest that at least four kinds of calcium exist in bound from in the cell, i. e., (1) loosely and (2) tightly bound calcium on the external surface of the cell membrane, (3) calcium localized in the internal surface of the cell membrane and (4) calcium stored in the intracellular store site, such as the sarcoplasmic reticulum. The intracellulary stored calcium, both (3) and (4), which can be mobilized by the action of certain drugs (NE, 5HT or caffeine), probably plays an important role for the regulation of the mechanical activity of vascular smooth muscle.

Animals↗
PubMed1977

Norvaline accumulation by regulatory mutants of Serratia marcescens.

A gene coding for desensitized L-threonine dehydratase was transduced with phage PS20 into a leucine accumulator of Serratia marcescens Sr41. The transductant converted L-threonine to alpha-ketobutyrate, a precursor of both norvaline and isoleucine. An isoleucine-valine auxotroph of the transductant accumulated large amount of norvaline from L-threonine as well as from D-threonine.

Cell-Free System↗
PubMed1977

[Two autopsy cases of adult central nervous system toxoplasmosis: light and electron microscopic studies (author's transl)].

Two autopsy cases of adult central nervous system toxoplasmosis were reported. Two cases treated with immunosuppressive agents and corticosteroids under a diagnosis of Hodgkin's disease were considered to be an acquired CNS toxoplasmosis associated with the underlying diseases. The first case, a 73 year old woman with Hodgkin's disease, showed toxoplasma lesions in the cerebrum. The second case, a 22 year old man with pulmonary tuberculosis, showed toxoplasma lesions in the cerebrum, basal ganglion, thalamus, cerebellum, pons, and medulla oblongatta. Each toxoplasma lesion showed small hemonecrotic softening. Toxoplasma cysts were seen around the hemonecrotic lesion. Encysted toxoplasma organisms were examined in detail with electron microscope.

Adult↗