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Biomedical subjects

K Tsutsui

Publications and source records attributed to K Tsutsui.

At least 253 records · Page 14Linked to original sources
PubMed1978

Clinical studies of "big ACTH": its physico-chemical characteristics.

The big ACTH fractions available from human plasma and pituitary glands and from porcine pituitary glands were physico-chemically characterized by gel filtration, disc electrophoresis and isoelectric separation. In the case of healthy human subjects, big ACTH fractions were isolated by gel filtration from plasma samples taken during states of acute ACTH hypersecretion such as the lysine-8-vasopressin, insulin or metopyrone tests though none of these fractions were isolated from plasma sampled under normal conditions. Even with no stimulation of ACTH secretion, patients with Cushing's disease gave plasma samples that contained an isolable big ACTH fraction, but such a fraction was hardly isolated from plasma taken from patient with Addison's disease. Both human pituitaries and porcine pituitaries contained an isolable big ACTH fraction. By a gel filtration analysis the molecular weight of the big ACTH was estimated to be higher than 20 000. Disc electrophoresis with an acrylamide gel indicated that big ACTH is strongly basic while small ACTH is more acidic than pH 8.3. Isoelectric separation revealed that the isoelectric point of human big ACTH is higher than pH 10.0 while that of small ACTH is about pH 6.8.

Addison Disease↗
PubMed1977

Role of hydrophobic interaction in hapten-antibody binding.

The precipitation reaction of bovine serum albumin coupled with p-azophenylleucine with homologous antibody was inhibited by several structurally related haptens. The isobutyl group substituent on alpha-carbon atom of the leucine residue contributed more than -5.8 Kcal/mol to the free energy of binding. This value was consistent with the free energy change expected from the transfer of n-butane from an aqueous environment to liquid n-butane. The observed contribution was explained, in terms of the hydrophobic interaction of the isobutyl group with the antigen binding site of the antibody molecule. These results were also compared with other hapten-antibody systems.

Animals↗
PubMed1977

Morphological studies of Gross virus-induced lymphoblasts by scanning electron microscopy.

The surface of Gross virus-induced murine lymphoblasts and C-type virus particles budding from these cells were investigated under the scanning electron microscope (SEM). The cells appeared spindle-shaped or roughly-rounded with extensive surface features consisting of microvilli, blebs and ruffled membranes. C-type virus particles were detected on the cell membrane as small spherical particles, distinguishable from the microvilli. Clustered virions were observed in some cases. However, the distribution of virions appeared to be random. The surface of the virion was smooth and had no globular units at high magnification. These morphological observations were confirmed in ultrathin sections.

AKR murine leukemia virus↗
PubMed1977

Mitochondrial sulfhydryl groups. A possible endogenous probe of conformational changes in the mitochondrial membrane.

The protein-bound sulfhydryl (SH) groups of the mitochondrial membrane were determined with Ellman's reagent in energized and non-energized configurational states of mitochondria and submitochondrial particles. When beef heart mitochondria were energized by respiration, there was a decrease in titratable protein-bound SH groups which varied according to substrate: NADH-linked substrates induced a decrease of about 10 nmol per mg of protein,succinate about 7, and ascorbate-tetramethyl-p-phenylene-diamine about 3. Similar changes occurred in phosphorylating submitochondrial particles. A decrease in SH titer was also observed in non-energized conditions, induced by hypotonic treatment and by some reagents inhibiting electron transport and oxidative phosphorylation and inducing orthodox configuration. These changes in protein-bound SH groups might be useful in analyzing the conformational states of mitochondrial membranes.

Animals↗
PubMed1976

The presence of phosphate-binding protein in inner mitochondrial membrane.

Phosphate-binding protein(s) was found in the inner mitochondrial membrane of calf heart by Sephadex G-200 and G-25 gel filtration. The binding activity was inhibited by N-ethylmaleimide and competed by a large amount of cold phosphate. The amount of phosphate bound to the fraction was 29 nmoles per mg of protein. Affinity chromatography with phosphate-bound Sepharose 4B confirmed the presence of phosphate-binding protein(s) in the active fraction of mitochondrial membrane fractionated by gel filtration.

Carrier Proteins↗