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Biomedical subjects

S Kurioka

Publications and source records attributed to S Kurioka.

26 records · Page 2Linked to original sources

Purification of fibrinogen using cationic detergent.

Stearyltrimethylammonium chloride was used to isolate human fibrinogen, and purified protein was obtained by removing the detergent bound to it. Medium consisting of 0.015--0.03 mM fibrinogen-detergent complex, 0.85 M NaCl, 0.03 M sodium caprylate, and 30 per cent ethanol was found to be effective for renaturation of fibrinogen from the complex. The purified fibrinogen did not form any fibrils on incubation for 15 days with Ca-2+ at pH 7.2, and 37 degrees. The clottability of the purified fibrinogen was over 99 per cent. Immunochemical studies showed that the purified fibrinogen produced one precipitation line with a mixture of anti-human fibrinogen and anti-human serum. Although highly purified, the fibrinogen preparation still contained a trace of plasminogen.

Calcium↗

Chemical modification of carboxyl groups of fibrinogen and its effect on the binding of cationic detergent.

Carboxyl groups of native human fibrinogen were modified with glycine methyl ester and 1-ethyl-3(3-dimethylaminopropyl)carbodiimide. It seemed likely that the modification occurred stepwise. Approximately 26% of the carboxyl groups of fibrinogen was modified finally. The modified fibrinogen had no interaction with cationic detergent, and did not form any complex with the detergent. In dilute acid, fibrinogen was observed to show only a slight interaction with cationic detergent. It is probable that the exposed and ionized carboxyl groups are essential for the formation of a complex between fibrinogen and cationic detergent.

Carbodiimides↗

Improved assay method for phospholipase C.

A lecithin sol dispersed with deoxycholate was found to be attacked by phospholipase C in the presence of calcium ion more rapidly than were any other lecithin sols. The inorganic phosphate could be released quantitatively from the acid soluble phosphate liberated from lecithin by an excess amount of alkaline phosphatase present in phospholipase C reaction mixture. A simple and accurate assay method for phospholipase C was developed with the sol and the alkaline phosphatase.

Alkaline Phosphatase↗

Detection of abnormal haemoglobin by capillary electrophoresis and structural identification.

Haemoglobin obtained from a male adult Ghanian with retinopathy, which was probably caused by haemoglobinopathy was analysed by capillary electrophoresis (CE) for clinical diagnosis. Two major peaks, which were in the ratio of nearly one, were detected. The elution times of these peaks (HbXI and HbXII) were faster than that of normal haemoglobin (HbA). The existence of two different abnormal types of haemoglobin was clear in the patient blood. The following sequence analysis revealed that the first peak (HbXI) was HbC and the second (HbXII) was HbS on the electropherogram, and that the patient was a heterozygote of HbS and HbC (HbSC disease). One of the diagnostic processes in a haemoglobin disease was shown by the combined use of CE, HPLC and a protein sequencer.

Adult↗

Assay of vitamin B6 in human plasma with graphitic carbon column.

A high performance liquid chromatographic (HPLC) procedure for measuring pyridoxal-5'-phosphate (PLP) and certain forms of B6 vitamers in plasma is presented here. This HPLC procedure consisted of a single graphitic carbon column with a fluorescence detector employing an isocratic eluent (15% acetonitrile: 1% perchloric acid: 0.05% sodium bisulfite). The graphitic carbon column is useful in acidic eluent without deteriorization. The relatively low fluorescent intensity of PLP under acidic conditions is improved by its derivatization with bisulfite in the eluent during chromatographic separation. Using this procedure, the detection limit of PLP is 50 fmol, and an aliquot of 5-50 microL of human plasma is required giving satisfactorily precise results within 5 min. We applied this method to the determination of PLP and certain B6 vitamers in human plasma after oral supplementation of pyridoxine.

Chromatography, High Pressure Liquid↗