著者

Kitano Motoo Hirano Masao Ishihara Takashi YOSHIDA Aichi HATTORI Shosaku UEDA Naoko CHIJIWA Takahito OHNO Motonori キタノ モトオ ヒラノ マサト イシハラ タカシ ヨシダ アイチ ハットリ ショウサク ウエダ ナオコ チヂワ タカヒト オオノ モトノリ 北野 元生 平野 真人 石原 尚 吉田 愛知 服部 正策 上田 直子 千々岩 崇仁 大野 素徳

出版者

鹿児島大学

雑誌

南太平洋研究 (ISSN:09160752)

巻号頁・発行日

vol.23, no.1, pp.11-18, 2002

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Trimeresurus flavoviridis (Tf) serum proteins were fractionated by anmnonium sulfate precipitation to five portions depending on the differences of its saturation percentages, that is, 0-20%, 20-30%, 30-40%, 40-50%, and 50-70%. The effects of these proteins on Tf venom-induced rat skeletal muscle damage were investigated with closer attention to histopathological features of impairment, necrosis, and regeneration ofmuscle fibers. The knowledges which portion of Tf serum proteins is effective for prevention of local lesions caused by Tf venom should shed light on the effective medical treatment after bitten by Tf snake. In consequence, it was found that the necrotic change of the rats inoculated with Tf crude venom together with the serum protein fraction of ammonium sulfate saturation percentage 40-50% was the smallest compared to those of the rats tested with other Tf serum protein fractions.

著者

MAEDA Iori SHIMOHIGASHI Yasuyuki IKESUE Koichi NOSE Takeru IDE Yuzuru KAWANO Keiichi OHNO Motonori

出版者

The Japanese Biochemical Society

雑誌

The journal of biochemistry (ISSN:0021924X)

巻号頁・発行日

vol.119, no.5, pp.870-877, 1996-05-01

参考文献数

25

被引用文献数

5

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The dipeptide benzyl amide H-D-Thr-Phe-NH-CH₂-C₆H₅ was found to inhibit chymotrypsin strongly (K_i=4.5×10^-6M) in a competitive manner. When a series of phenyl amides H-D-Thr-Phe-NH-(CH₂)<i>_n</i>-C₆H₅ (<i>n</i>=0-4) were tested, inhibitory potency peaked at n=1 (benzyl amide). Incorporation of a methyl group into the benzyl methylene resulted in formation of stereoisomers, H-D-Thr-Phe-NH-(<i>R</i> or <i>S</i>)-CH(CH₃)-C₆H₅, with considerably different inhibitory potencies. The <i>R</i>-isomer was as active as the benzyl amide, while the <i>S</i>-isomer was about 30-fold less active than the benzyl amide. Furthermore, when a fluorine atom was introduced into the para-position of the amide-benzyl group, the resulting H-D-Thr-Phe-NH-CH₂-C₆H₄(<i>p</i>-F) showed considerably enhanced inhibitory activity (about 5-fold, <i>K</i>_i=9.1×10^-7M). In conformational analysis by 400MHz ¹H-NMR, all dipeptides having D-Thr-Phe backbone structure showed large upfield shifts of D-Thr-βO<i>H</i> (shifts in ppm, 0.09-0.17), D-Thr-βC<i>H</i> (0.23-0.32), and D-Thr-γC<i>H</i>₃ (0.38-0.53), indicating the presence of shielding effects from the benzene ring. In addition, NOE enhancements between the D-Thr-γCH₃ and Phe-phenyl groups were evidenced by measurements of two-dimen-sional NOESY spectra and NOE difference spectra. These observations demonstrated the spatial proximity of these side chains, which is due to side chain-side chain CH/π interaction. All these results support the idea that the amide-benzyl group binds at the chymotrypsin S₁, site, while the hydrophobic core with CH/π interaction binds at the S₂ or S₁' site.