ユリ根中トリプシンインヒビター(LTI-II-4)の精製とその性質

Several proteins from lily bulb for foodstuffs showed strong inhibitory activity toward bovine trypsin. A trypsin inhibitor (LTI-II-4) was purified from lily bulb by a method including column chromatographies on CM-Sepharose CL-6B and DEAE-Sepharose GL-6B and high-pressure liquid chromatography. Purified LTI-II-4 had a molecular weight of 21,000. The amino acid composition was characterized by high contents of glycine, aspartic acid and serine. The inhibitor contained 4 halfcystines in its constituent amino acids. The N-terminal 25 and the C-terminal 3 residues of LTI-II-4 were sequenced. The Inhibitor was stable in a wide pH range under 50℃ and was unstable at the higher temperatures than 80℃. The reactivesite amino acid of LTI-II-4 was assumed to be lysine. The inhibitor didn\u27t inhibit elastase and subtilisin. From these results, the inhibitor LTI-II-4 is assumed to belong to the Kunitz soybean trypsin inhibitor family

Optical studies on the purified eggplant trypsin inhibitor (Agricultural Chemistry)

ナス果皮より均一に精製したトリプシン・インヒビターについてその光学的性質を検討した。各種pHにおいて, 紫外吸収スペクトルを測定したがpH 3.1から9.4の範囲では, チロシンおよびフェニールアラニン残基による同じスペルトルを示したが, pH 10以上ではチロシン残基のイオン化による著しい変化が認められた。またアミノ酸分析で確認されているようにトリプトフアンを含まないことは, 紫外吸収スペルトルからも明らかであった。275nmで励起した蛍光スペクトルが測定されたが, pH 3.1から9.4の範囲では蛍光強度は, ほゞ一定であり10以上で減少した。またCDスペクトルの測定結果はこのインヒビターが, ほとんどヘリックス構造やβ-構造を含まないことを示している

Occupational Exposure to Gaseous and Aerosolized Volatile Organic Compounds in Flight Line Crews Using Different Types of Jet Fuel

We conducted a study to characterize the occupational chemical exposure to JP-8 ［a kerosene-based jet fuel used widely for both military and commercial aircraft） and JP-4 （a naphtha – and kerosene-based jet fuel that is used by the Japan Air Self-Defense Force （JASDF）］. The study population included 90 volunteer subjects from JASDF and United States Air Force bases in Japan. The individual exposure to 48 volatile organic compounds （VOCs） was measured in C-130 （a cargo aircraft） flight line crews and non-exposed control subjects （workers in the Yokota and Kadena hospitals）. The individual air samples were collected during a typical work shift using a compact battery-operated personal air sampler with activated charcoal for gaseous VOCs and with a cascade impactor for aerosolized VOCs （diameter:＜6.6µm）. Each collected sample was analyzed by gas chromatography. Subjects in the JP-4 group were mainly exposed to gaseous aromatics and shorter straight-chain alkanes including carcinogenic benzene and neurotoxic hexane, while the subjects in the JP-8 group were exposed to aerosolized alkanes with a longer straight chain such as tridecane. In conclusion, this study revealed the characteristics of chemical exposure according to the fuel type in the flight line environment. The results suggest the health risks associated with each fuel type and the protective measures that should be employed. Aerosolized tridecane or aerosol containing tridecane might be causing the complaints from workers using kerosene-based fuel. None of the subjects were exposed to VOCs at levels exceeding recommended exposure limits

X-rays Induce Dose-dependent and Cell Cycle-independent Accumulation of p21sdi1/WAF1

Cell cycle arrest at the G1 checkpoint is governed by a function ofwild-typep53. We assessed the behavior of the sdi1 gene, which codes for a 21kDa potent inhibitor of cdk/cyclins, after X-irradiation. X-irradiation induced sdi1 mRNA accumulation and G1 arrest only in cells possessing wild-type p53. Elevation of p21sdi1/WAF1 was preceded by p53 accumulation, which occurred despite p53 mRNA constancy in normal cells growing in the log phase. The quantity of accumulated p53 and p21sdi1/WAF1 was radiation dose dependent. A decrease in the S phase cell population in normal cells observed after irradiation reached a minimum at less-than-maximum levels of p53 and p21sdi1/WAF1 Furthermore, an accumulation of p53 and p21sdi1/WAF1 was also observed when cells were synchronized in the G0, G1 and S phase and X-irradiated. These results indicated that an X-ray induced p53 and p21sdi1/WAF1 accumulation mechanism exists throughout the cell cycle, and that the signal strength induced by X-irradiation is dose-dependent.This publication is based on research performed at the Radiation Effects Research Foundation (RERF), Hiroshima and Nagasaki, Japan and is supported in part by Grants-in-Aid (S7-l) for Cancer Research from the Ministry of Health and Welfare