| Project/Area Number |
61570041
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| Research Category |
Grant-in-Aid for General Scientific Research (C)
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| Allocation Type | Single-year Grants |
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| Research Field |
General physiology
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| Research Institution | Hamamatsu University School of Medicine |
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Principal Investigator |
TAKADA Akikazu Department of Physiology, Hamamatsu University, School of Medicine, 医学部, 教授 (80092980)
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| Co-Investigator(Kenkyū-buntansha) |
MAKINO Yasuhiro Dept. Physiology, Hamamatsu University, School of Medicine, 医学部, 助手 (50173729)
SUGAWARA Yoshiaki Dept. Physiology, Hamamatsu University, School of Medicine, 医学部, 助手 (30154462)
TAKADA Yumiko Dept. Physiology, Hamamatsu University, School of Medicine, 医学部, 助手 (90092981)
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| Project Period (FY) |
1986 – 1988
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| Keywords | plasminogen / carbohydrate chain / fluorescence / tertiary structure / tranexamic acid epsilon aminocaproic acid / グリコペプチダーゼ / エラスターゼ |
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| Research Abstract |
Plasminogen has two isozymes, one (plg I) having two carbohydrate chains at Arg288 and Thr345, and other (plg II) having one at Thr345. Native plasminogen (Glu-plg) I and II have the same primary structures, but its tertiary structures are different. Glu-plg I has more random structure and less turn than Glu-plg II in the secondary structure. Comparison of the intensity of the tryptophan dependent fluorescence indicated that Glu-plg I has larger intensity than Glu-plg II. Fluorescence polarization shows that the rotational relaxation time of the N-terminal part of Glu-plg I was shorter than that of Glu-plg II, indicating more freedom in the micro-Brownian movement of the N-terminal part of Glu-plg. Binding of lysine analogues such as tranexamic acid or EACA (epsilon aminocaproic acid) changes the tertiary structure of Glu-plg, resulting in larger intrinsic fluorescence intensity of Glu-plg I in comparision to that of Glu-plg II. kd of the interaction of lysine analogues with Glu-plg I were smaller than those with Glu-plg II. N-terminal peptide of Glu-plg I is more easily cleaved by plasmin than that of Glu-plg II, indicating a portion near Lys77-Lys78 of Glu-plg I being exposed than that of Glu-plg II. Elastase degrades Glu-pig II faster than Glu-plg I. The presence of two carbohydrate chains protect Glu-plg I from elastase induced degradation, due to a steric hindrance provided by these chains.
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