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用分子置换法成功地解得了MBILF-BTRY的晶体结构,并得到了它的立体结构模型。绿豆胰蛋白酶抑制剂属于絲氨酸蛋白酶抑制剂中结构最复杂的Bowman-Birk型抑制剂。这一类型抑制剂的立体结构以前尚未见报道。MBILF-BTRY复合物晶体的晶胞参数为a=62.99,b=63.54,c=69.70,α=β=γ=90°,空间群为P2_12_12_1,复合物分子量约为27500daltons。用理学电机的Ru-300型转靶X光机及AFC-5型四园衍射仪收集了分辨率为3范围内的独立衍射点5142个。以蛋白质数据库所取得的牛胰蛋白酶分子的座标为 相似文献
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本文研究了河蚌(Cristaria plicata,Leach)闭壳肌的平滑部分籍乙酰胆碱引起的保留性收缩现象,在电子显微镜下观察了在固定的超薄切片中粗细丝的排列和在游离的粗丝中结构的细节.粗丝呈现大角度的转折,有时几根粗丝互相缠绕.细丝排列不规则,一根细丝可同许多根粗丝相联结.当此平滑肌恢复到松弛状态时,粗、细丝平行排列.我们认为:粗、细丝的杂乱分布并交织成三维网格,是保留性收缩的结构基础,它使粗、细丝不易定向滑动,需要时间恢复有序的排列。 相似文献
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We have examined the arrangements of the thick and thin filaments of the smooth mus-cle of the adductor of the bivalve Cristaria plicata, Leach, in the catch state induced byacetylcholine, both in ultrathin sections and in separate filaments. The thick filaments areheavily bent and entangled and the thin filaments irregularly arranged. One thin filamentmay be attached to several thick filaments. When the muscle is in the relaxed state, the twokinds of filaments are seen to be in Parallel. However, no difference could be observed in theperiodic strusture of the paramyosin core of the thick filaments in the relaxed state or in catch.Both cross-striated and checkerboard types coexist. It seems that phase transition is not di-rectly related to catch. We propose that the disordered arrangements of the thick and thinfilaments and the formation of three-dimensional anastomosed networks are the structural basisfor catch, with a consequent loss of the capability of directional sliding of the filaments andrequiri 相似文献
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Crystal structure of MBILF-BTRY complex was successfully solved by molecular replacement method and its 3-dimensional molecular model was thereby derived. Mung bean trypsin inhibitor belongs to Bowman-Birk inhibitor group, which is by far the most complicated among the ten fundamental groups of serine protease inhibitor. Neither the 3-dimensional structure of Bowman-Birk inhibitor group nor the stereoscopic conformation of its complex with protease has ever been reported. The crystallographic data of MBILF-BTRY complex are found to be a=.... 相似文献
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The trypsin inhibitor from mung bean has a molecular weight of 7984, consisting of two active domains and seven disulfide bonds. It belongs to the Bowman-Birk inhibitor. This inhibitor has been crystallized in two crystalline forms either by dialysis or by batch method. One is tetragonal with unit cell of symmetry P4_122(or P4_322) and dimensions a=b=49.21, c=158.07, each asymmetric unit containing three molecules. Another is orthorhombic with unit cell of symmetry P2_12_12 and dimensions a=39.65, b=57.18, c=52.02, each asymmetric unit containing two molecules. 相似文献
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从绿豆中提取的胰蛋白酶抑制剂,分子量为7984,具有两个活性中心,7对二硫键,属于Bowman-Birk抑制剂类型。用透析法和静置法生长出四方双锥和斜方柱两种晶体。用X1线旋进照相法测定它们的晶胞参数。四方双锥晶体属四方晶系,空间群P4_122(或P4_322),a=b=49.21(?),c=158.07(?)。每个晶体学不对称单位包含三个分子。斜方柱晶体属正交晶系,空间群P2_12_12,a=39.65(?),b=57.18(?),c=52.02(?)。每个晶体学不对称单位包含两个分子。 相似文献
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The Lys fragment of mung bean trypsin inhibitor can combine with bovine trypsin to form a complex at an equal molar ratio. The single cxystals of the complex were obtained by using the micro-still-setting method and the X-ray diffraction extended to 1.8 resolution. Its space group is P2_12_12_1 wlth cell dimensions α=62.9(1), b=63.4(1) and c=69.7(2). There is one complex molecule in a crystallographic asymmetric unit. 相似文献