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Biomedical subjects

S Maehara

Publications and source records attributed to S Maehara.

At least 55 records · Page 3Linked to original sources
PubMed1982

Purification and partial characterization of two forms of urinary trypsin inhibitor.

Crude urinary trypsin inhibitor was obtained by DEAE-cellulose column chromatography from normal fresh urine. By the purification of the crude urinary inhibitor on successive chromatography methods using Sephacryl S-200, DEAE-cellulose, CM-Sepharose CL-6B and Sephadex G-100, we detected two forms of urinary trypsin inhibitor: form I and form II. The specific activity of form I increased approx. 4-fold with a recovery of 60%, as compared to that of crude urinary trypsin inhibitor. N-terminal amino acids of form I and form II were determined to be alanine and valine, respectively. Molecular weights of forms I and II were estimated to be 67000 and 28000 by gel filtration on Sephadex G-100 and to be 43000 and 19000 by SDS-polyacrylamide gel electrophoresis. S-carboxymethylated form I migrated as a single band corresponding to a molecular weight of 59000 in SDS-polyacrylamide gel electrophoresis. From the results of the determination of a single N-terminal amino acid of form I and a single band of S-carboxymethylated form I, it is indicated that it is composed of single polypeptide chain. And the present study suggests that form I is a native form of trypsin inhibitor in normal human urine and form II is a fragmented product from form I in the purification steps.

Amino Acids↗
PubMed1982

Low molecular weight trypsin-plasmin inhibitors isolated from papain treated urinary trypsin inhibitor.

Papain treatment of human urinary trypsin inhibitor (UTI67; mol. wt. 43,000 by SDS-polyacrylamide gel electrophoresis, specific activity 1,897 U/mg protein) produced four new protease inhibitors, which were highly purified by gel chromatography on Sephadex G-100 and isoelectric focusing. The purified inhibitors (UTI26, UTI9-I, UTI9-II, and UTI9-III) were shown to be homogeneous by polyacrylamide disc gel electrophoresis, and had apparent molecular weights of 26,000, 9,000, 9,000, and 9,800, respectively, by sodium dodecyl sulfate gel electrophoresis. During enzymatic degradation of UTI67, the amino acid compositions changed to more basic, and the isoelectric point increased from pH 2.0 (UTI67) to pHs 4.4, 5.2, 6.6, and 8.3 (UTI26, UTI9-I, UTI9-II, UTI9-III), respectively. Both the parent and degraded inhibitors had anti-plasmin activity as well as antitrypsin and anti-chrymotrypsin activities. Much higher anti-plasmin/anti-trypsin and anti-plasmin/anti-chymotryspin activities were observed in the degraded inhibitors than in the parent UTI67. They competitively inhibited human plasmin with Ki values of 1.13 X 10(-7) - 2.12 X 10(-6) M (H-D-Val-Leu-Lys-pNA substrate). The reactions were very fast and the active site of the inhibitors of plasmin was thought to be different from that to trypsin or chymotrypsin.

Amino Acids↗
PubMed1982

Immunochemical studies of high and low molecular forms of urokinase.

The immunochemical properties of high and low molecular forms of urokinase (HMW-UK, MW 53,000, 124,000 IU/mg protein; LMW-UK, MW 32,000, 230,000 IU/mg protein) were studied with specific antisera against the functionally active heavy chain (H chain, MW 31,000, 201,000 IU/mg protein) and the light chain (L chain, MW 18,000) of HMW-UK. Using a double immunodiffusion technique, LMW-UK did not demonstrate L chain antigenicity in the molecule. Anti-L-chain serum exerted no effect on LMW-UK and the H chain, but anti-H-chain serum strongly inhibited the fibrinolytic activity of all the active enzymes (HMW-UK, LMW-UK, and H chain). Anti-L chain serum was found to exert an antifibrinolytic effect on HMW-UK.

Animals↗
PubMed1981

Immunochemical studies of human urinary trypsin inhibitor.

Antisera against purified urinary trypsin inhibitor (UTI-I, molecular weight 67,000) and UTI-III (molecular weight 23,000) were first produced in rabbits. Both anti-UTI-I and anti-UTI-III sera formed a single immunoprecipitin line with human plasma inter-alpha-trypsin inhibitor (I alpha TI), whereas two immunoprecipitin lines were formed with crude urine. It was speculated that both UTI-I and UTI-II might be present in normal human urine. In the present study, the inhibitory effects of anti-UTI sera on UTI activity were examined by three different assay methods. The results indicated that the inhibitory effect was almost immediate. Although the inhibitory effect of anti-UTI-III serum on UTI-III was almost of the same degree of completeness for the three assay methods. UTI-I was partially inhibited by the anti-UTI-I serum when residual trypsin activity was measured by the caseinolytic or fibrinolytic assay method. This discrepancy was considered to be due to the difference in conformational change between UTI-I and UTI-III by antigen-antibody reaction.

Alpha-Globulins↗