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Biomedical subjects

Y Takada

Publications and source records attributed to Y Takada.

At least 721 records · Page 40Linked to original sources
PubMed1979

Degradation of uric acid to urea and glyoxylate in peroxisomes.

The distribution of enzymes involved in purine degradation in fish and crustaceous liver was examined by centrifugation in a sucrose density gradient. In mackerel, yellow mackerel, and prawn liver and mantis club hepatopancreas, uricase and allantoinase were located only in the peroxisomes and in the soluble fraction from broken peroxisomes, and allantoicase was located only in the peroxisomes. Uricase and allantoinase seem to be located in the peroxisomal matrix and allantoicase in the peroxisomal membrane. Adenase, guanase, and xanthine oxidase were present only in the soluble fraction of mackerel liver.

Animals↗
PubMed1979

Relationships between the haemolytic activities of the human complement system and complement components.

The relationships between the haemolytic activities of complement and its components were studied. The activities studied included CH50 (classical pathway), AP50 (alternative pathway), CV50 (early part of alternative pathway) and C(3--9)H50 ((the late part of both pathways). The components included C3, C4, C5, C9, B and D. There was a good correlation between CH50 and AP50. AP50 had a good correlation with B and CV50. There was no correlation between AP50 and C(3--9)H50, and none between C(3--9)H50 and C5 or C9. AP50 may primarily represent changes in the early part of the alternative pathway. C(3--9)H50 is not influenced by respective changes in the amounts of C5 or C9. Since cell lesion is now considered to be caused by a unit of C5b to C9, a change in each component of C5 to C9 may not influence haemolytic activity.

Adult↗
PubMed1978

Peroxisomal localization of serine:pyruvate aminotransferase in human liver.

The distribution of L-serine:pyruvate aminotransferase (EC 2.6.1.51) in human liver was examined by centrifugation in a sucrose density gradient. The enzyme was located only in the peroxisomes and in the soluble fraction. The peroxisomal and soluble enzymes were highly purified and characterized. The two enzyme preparations had nearly identical properties, suggesting that the soluble enzyme is from broken peroxisomes. The two enzyme preparations showed different properties from rat liver serine:pyruvate aminotransferase (Noguchi, T., Okuno, E., and Kido, R. (1976) Biochem. J. 159, 607-613).

Cytosol↗
PubMed1978

Purification and properties of peroxisomal pyruvate (glyoxylate) aminotransferase from rat liver.

Pyruvate (glyoxylate) aminotransferase from rat liver peroxisomes was highly purified and characterized. The enzyme preparation has a mol.wt. of approx. 80,000 with two identical subunits, and isoelectric point of 8.0 and a pH optimum between 8.0 and 8.5. The enzyme catalysed transamination between a number of L-amino acids and pyruvate or glyoxylate. The effective amino acceptors were pyruvate, phenylpyruvate and glyoxylate with serine, and glyoxylate and phenylpyruvate with alanine as amino donor. These properties and kinetic parameters of the enzyme are remarkably similar to those previously described for mitochondrial alanine-glyoxylate aminotransferase isoenzyme 1 from glucagon-injected rat liver [Noguchi, Okuno, Takada, Minatogawa, Okai & Kido (1978, Biochem. J. 169, 113-122].

Alanine Transaminase↗
PubMed1978

The effects of metal ions on esterase activities of urokinase.

The esterase activity of highly purified human urokinase on Nalpha-acetylglycl-L-lysine methyl ester is strongly inhibited by 1 X 10(-5) to 1 X 10(-2)M Cu++, Hg++, Ni++, Co++, Fe+++, and Mn++ solutions, whereas Na+, K+, Ca++, and Mg++ are weakly effective. This inhibition is parallel with the inhibition of activation of plasminogenby urokinase. There is no simple linear relation between inhibiton and concentration. Addition of ethylenediaminetetraacetate or electrodialysis fully reactivates the inhibited enzyme. These results are discussed in relation to similar effects of ions on trypsin.

Dipeptides↗
PubMed1978

Subcellular distribution of pyruvate (glyoxylate) aminotransferases in rat liver.

The distribution of pyruvate (glyoxylate) aminotransferases in the particulate fraction of rat liver homogenates was examined by centrifugation in a sucrose density graident. Aminotransferase activities towards serine, phenylalanine and histidine with pyruvate and those towards phenylalanine and histidine with glyoxylate were nearly identically distributed. Some 50-55% of the particulate activity was localized in the peroxisomes and the remainder in the mitochondria. Most of alanine-glyoxylate aminotransferase activity was localized in the mitochondria, with some activity in the peroxisomes. Glucagon injection resulted in increases of these enzyme activities in the mitochondria, but not in the peroxisomes.

Animals↗