Yoshiaki Tanaka

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.

Preflight performance of the Astro-E hard X-ray detector

The hard x-ray detector (HXD) is one of the three experiments of the Astro-E mission, the fifth Japanese X-ray Satellite devoted to studies of high energy phenomena in the universe in the x-ray to soft gamma-ray region. Prepared for launch at the beginning of 200 via the newly developed M-V launch vehicle of the Institute of Space and Astronomical Science, the Astro-E is to be thrown in to a near-circular orbit of 550 km altitude, with an inclination of 31 degrees. The flight model has been finished assembled this year, and we carried out various tests to verify the performance. We acquired the background spectrum at sea level, and confirmed that our system is operating effectively in reducing the background level. The HXD will observe photons in the energy range of 10-600 keV, and the calculations based on the preflight calibration suggest that the HXD will have the highest sensitivity ever achieved in this energy range. We also verified that our electronic system will maintain its performance against charged particle events expected in orbit.

Immunochemical determination of the serum protein reacting with antibody against human urinary trypsin inhibitor by single radial immunodiffusion: use of polyethylene glycol

A single radial immunodiffusion method is described for determining the serum protein which reacts with antibody against the urinary trypsin inhibitor, but does not react with anti-inter-alpha-trypsin inhibitor antibody. Since the amount of this protein could not be determined with an agar plate containing antibody alone, we first prepared an agar plate containing 4% polyethylene glycol 6 000 and 1 mg of anti-urinary trypsin inhibitor gamma-globulin and confirmed that the amount of this protein could be measured accurately from the sizes of precipitin rings after 72 h incubation at room temperature. Levels of this serum protein, alpha 1-antitrypsin, alpha 2-macroglobulin and inter-alpha-trypsin inhibitor were measured in normal human serum by the single radial immunodiffusion method, and it was confirmed that the level of this serum protein did not correlate with the levels of these 3 other proteins.