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T Uchida

Publications and source records attributed to T Uchida.

At least 1,243 records · Page 69Linked to original sources
PubMed1981

Purification of ribonuclease T1 by affinity chromatography.

The purification procedure of ribonuclease T1 was greatly improved by introducing affinity chromatography with a new adsorbent, guanosine 5'-phosphate-aminohexyl-Sepharose 4B. The enzyme was purified by only four steps with a high yield (68%) from Taka-Diastase powder. The purified enzyme preparation gave a single peak of protein with a small shoulder on DEAE-cellulose column chromatography. The peak fraction, amounting to approximately 90% of total proteins, was homogeneous ribonuclease T1. Moreover the shoulder fraction was shown to contain another form of ribonuclease T1 electrophoretically distinguishable from the original one. Comparison of the properties of the fraction containing almost equal amounts of both components with those of original ribonuclease T1 shows that the other form of T1 is identical with the original one in respect to amino acid composition and base specificity. We propose to designate this new form and original one as ribonuclease T1-B and T1-A, respectively.

Amino Acids↗
PubMed1981

An affinity adsorbent, 5'-adenylate-aminohexyl-sepharose. I. Purification and properties of two forms of RNase U2.

An affinity adsorbent, 5'-adenylate-aminohexyl-Sepharose 4B, was prepared by the periodate oxidation of AMp followed by coupling and condensation with amino-hexyl-Sepharose 4B. RNase U2, a purine-specific RNase, was specifically bound to this adsorbent at pH 4.5 and eluted critically at pH 5.9 in the presence of 1 M NaCl, corresponding to the pH dependence of the binding of 2'-AMP to RNase U2. By using this affinity chromatography as a main tool, a simplified and effective purification method for RNase U2 was established with a high yield of 58%. Another form of RNase U2 with low specific activity, named RNase U2-B, was eluted at a slightly higher pH from this adsorbent. RNase U2-B was indistinguishable from the original enzyme (RNase U2-A) in base specificity, affinity for ApA, molecular weight and amino acid composition, but was clearly different in specific activity, molecular activity for ApA, isoelectric point and conformation of molecule. This affinity adsorbent is also effective for the detection or isolation of small amounts of base-specific RNases in crude cell extract.

Adenosine Monophosphate↗
PubMed1981

An affinity adsorbent, 5'-adenylate-aminohexyl-sepharose. II. Purification and characterization of multi-forms of RNase T2.

RNase T2 bound to an affinity adsorbent, 5'-adenylate-aminohexyl-Sepharose 4B, specifically at pH 4.5. The colorless enzyme was eluted only by the simultaneous addition of 2'(3')-AMP (1 mM) and NaCl (greater than 1 M) at pH 4.5. By applying this affinity chromatography to the purification of RNase T2, pure enzyme with a specific activity of 60 was obtained in only four steps and the yield was about 10 times higher than that of the previous purification method. This enzyme preparation was found to be heterogeneous in molecular weight and was separated into two fractions on Sephadex G-75 gel filtration. As the smaller enzyme with a molecular weight of 36,000 was identical with RNase T2 in every property examined, we tentatively designated the larger one with an apparent molecular weight of 80,000 as high molecular weight RNase T2 (RNase T2-L). RNase T2-L was still heterogeneous and was separated into five fractions, RNases T2-L 1-5, by repeated Sephadex G-150 gel filtration. The amino acid and carbohydrate analyses revealed that each of these fractions has a protein moiety in common with RNase T2 and the heterogeneities were due to the carbohydrate content, mainly galactose content.

Adenosine Monophosphate↗
PubMed1981

Molecular multiplicity of nuclease TT1 from Thermus thermophilus HB8.

Purified nuclease TT1 from Thermus thermophilus HB8 has multimolecular weight forms, each of which is composed of three different subunits, alpha (10.8 x 10(4)), beta (7.8 x 10(4)), and gamma (4.1 x 10(4)). The molecular weights of this enzyme were estimated by gel filtration, polyacrylamide gel electrophoresis and equilibrium sedimentation. It was found that most of the enzyme has a molecular weight of about 22 x 10(4) being a monomer having the subunit composition of alpha beta gamma. The remaining part of the enzyme has larger molecular weights and is considered to be size-isomers of alpha beta gamma. The alpha-helical content, 5.5--6.5%, and the beta-structure, about 28%, were estimated from the CD spectrum at 4 degrees C.

Circular Dichroism↗
PubMed1981

The effect of RES blockade on red blood cell survival.

The effect of RES blockade on the survival of heat-damaged and antibody coated red blood cells was evaluated in C3H mice. RES function of C3H mice was determined by the survival of 59Fe-labeled, heat-damaged red blood cells at 49 degrees C for 30 min. When animals were treated with an intravenous injection of non-labeled, heat-damaged red blood cells for the blockade of RES, red blood cell destruction was depressed in non-splenectomized and splenectomized mice. In the survival or organ distribution of 59Fe-labeled, antibody-coated red blood cells, no difference was noted between animals with and without blockade. These findings suggest that heat-damaged red blood cells were destructed predominantly in the splenic RES and antibody coated cells were not broken down only by the splenic RES.

Animals↗
PubMed1981

Human hepatocellular carcinoma and putative precancerous disorders: their enzyme histochemical study.

An enzyme histochemical study was performed to investigate abnormal enzyme activity in human hepatocellular carcinoma (HCC) and, by application of these staining reactions to noncancerous liver disorders, to clarify the true nature of putative percancerous lesions. The enzyme activity of hepatocytes in cirrhotic livers, hepatitis B virus (HBV)-positive cells, and dysplastic liver cells was investigated. Although the tumor cells in HCC gave an intensively positive reaction for gamma-glutamyl transpeptidase activity at the cytoplasm and the whole-cell membrane, they were essentially deficient in glucose-6-phosphatase, alkaline phosphatase, acid phosphatase, and nonspecific esterase activities. Cirrhotic liver showed loss of the orderly zonal difference of enzyme activity that is present in normal liver. However, a pattern of enzyme deviation similar to that of HCC was not recognized anywhere. Neither HBV-positive hepatocytes nor dysplastic liver cells were shown enzymatically to be direct precusors of HCC.

Acid Phosphatase↗
PubMed1981

Localization of galactocerebroside in oligodendrocytes, myelin sheath and choroid plexus.

The location of galactocerebroside in brain was investigated by using a specific anti-galactocerebroside antibody which was purified by affinity chromatography. It was found that galactocerebroside is distributed not only in oligodendrocytes and myelin but also in epithelial cells of the ependymal layer of the ventricle and choroid plexus. Biochemical analysis also revealed the presence of galactocerebroside and its sulfated derivative, sulfatide, in the choroid plexus.

Animals↗
PubMed1981

[Clinical evaluation of cefotiam in internal medicine, with special reference to infectious disease associated with hematological disorders (author's transl)].

Clinical evaluation of cefotiam (panspolin), a new cephem antibiotics, was performed in the infectious disease associated with hematological disorders and in the respiratory system. In hematological dis orders, 40% of good and 25% of fair results were obtained in clinical effects. In respiratory infections, however, 92% of good results were obtained. Opportunistic infection due to Gram-negative bacilli are often experienced in patients with leukemia. Since cefotiam has sufficient bacteriocidal effects in broad spectrum, it would be a good therapeutic agent against infectious diseases associated with hematological disorders.

Adolescent↗