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Biomedical subjects

K Murakami

Publications and source records attributed to K Murakami.

At least 1,333 records · Page 74Linked to original sources
PubMed1976

Molecular properties and a nonidentical trimeric structure of purine nucleoside phosphorylase from chicken liver.

Some molecular properties of crystalline purine nucleoside phosphorylase (purine nucleoside: orthophosphate ribosyltransferase, EC 2.4.2.1) from chicken liver were investigated and discussed. The molecular weight of the native enzyme was determined to be 89 000 by gel filtration and sedimentation coefficient, and 90 000 by sedimentation equilibrium, respectively. The enzyme was assumed to be a trimer consisting of one large subunit and two identical small subunits. The molecular weights of two different sized subunits were determined to be 32 000 and 28 000 by sodium dodecyl sulfate gel electrophoresis, and 30 000 and 27 000 by 6 M guanidine hydrochloride gel filtration. The amino acid composition was determined and the partial specific volume was estimated to be 0.735 ml/g.

Amino Acids↗
PubMed1976

Flavodoxin: an allosteric inhibitor of AMP nucleosidase from Azotobacter vinelandii.

Flavodoxin, which participates in nitrogen fixation, was found to be a potent allosteric inhibitor of AMP nucleosidase [EC 3.2.2.4] from Azotobacter vinelandii. It inhibited the enzyme by decreasing its affinity for ATP without affecting the maximum velocity. The inhibition constant for flavodoxin was estimated to be 10 muM, which is within the range of physiological concentration in the cells. The concentration of flavodoxin able to alter the activity in vitro suggests that this phenomenon could be of significance in the regulation of flavin biosynthesis in vivo. Flavin mononucleotide (FMN), a prosthetic group of flavodoxin, was also found to act as an allosteric inhibitor. Since no inhibitory action of apo-flavodoxin was observed, it was concluded that the FMN chromophore of the flavodoxin is responsible for the inhibition of the enzyme by this protein.

Adenosine Monophosphate↗
PubMed1976

Post-traumatic anterior pituitary insufficiency developed in a patient with partial lipodystrophy.

A case of partial lipodystrophy developing anterior pituitary insufficiency, chronic glomerulonephritis and pulmonary fibrosis was reported. The patient died of respiratory failure secondary to pituitary crisis during the hospital course. From the clinical course in recent several years and the postmortem examination the head injury following car accident in the past history was considered to be the most plausible cause of hypopituitarism. The etiology of pulmonary fibrosis remained unresolved.

Adrenal Glands↗
PubMed1976

Flexible structure of immunoglobulin G molecule. Fluorescence depolarization studies on hapten-antihapten antibody interactions using arylnaphthalenesulfonates as the ligands.

Fluorescence depolarization studies on immunoglobulin G, Fab'2 and Fab' fragments were carried out using isomeric anilinonaphthalenesulfonates and their corresponding rabbit antibody systems, and the values of the relaxation time rho(h) were calculated. From the results it was confirmed that the IgG and Fab'2 fragment have a certain degree of segmental flexibility, and suggested that these divalent antibody molecules have the same order of flexibilities. Furthermore, the rhoh values of the Fab' fragments from each antibody preparation were also determined and conflicting results were obtained with the samples from two different kinds of antibody systems against the isomeric ligands. The results were discussed with special references to the orientation of ligands bound to the antibody combining sites.

Anilino Naphthalenesulfonates↗
PubMed1976

[A new endoscopic method: the peroral choledocho-pancreatoscopy (author's transl)].

A new very thin glass fiber endoscope ("baby scope") has been developed, which can be passed through the channel of a modified duodenoscope ("mother scope") for catheterization of the choledochus or of the pancreatic duct. Peroral choledocho-pancreatoscopy (PCPS) was performed in 9 patients, the endoscopic results are presented. Other new auxiliary instruments for diagnostic or therapeutic purposes in biliary or pancreatic diseases are described: a brushing catheter, a special biopsy forceps, a retention probe and a balloon-tipped catheter.

Catheterization↗