摘要
α－苦瓜子蛋白是一种单链核糖体失活蛋白，具有Ｎ－糖苷酶活性，２．０Ａ分辨率的三维结构已经测定。α－苦瓜子蛋白中总共有３５３个氢键，其中主链原子间氢键１６５个，主链原子与侧链原子间氢键５４个，侧链原子间氢键２１个，蛋白分子中原子与溶水剂的氢键１１３个，主链Ｃ＝Ｏ，主链ＮＨ及侧链分子结构中有９５％的残基能生成氢键，Ａｓｐ．Ｇｌｕ、Ａｓｎ、Ｇｌｎ具有较强的生成多个氢键的能力，并对１３个没有任何氢键的残基作了分析。Ａｎ、Ｌｅｕ、Ｉｌｅ、ＧｌＵ、Ｇｌｎ在α螺旋中出现税率较大，Ｖａｌ、Ｌｅｕ、Ｔｙｒ、Ｉｌｅ、Ｔｈｒ在β结构中占了一半以上，Ａｒｇ容易形成远程的氢键，而Ｓｅｒ、Ｔｈｒ则容易形成近程氢键。某些氢键，特别是保守残基间的氢键，对形成蛋白分子局部特征构象和活性部位的特征构象有影响，α－苦瓜子蛋白的特定折叠方式对其与溶剂水分子成氢键有影响。
?Momorcharin is a kind of Ribosome-inactivating protein with N-glycosidase activity.The structure has for solved at 2.0A resolution.There are 353 hydrogen bonds in the α-Momereharin model. The numbers of hydrogenmade by main chain cathouly and amido groups are 165, hydrogen bonds between mainchain and sideChain are 54, hydrogen bonds between sidechain and sidechain are 21. whereasprotein atom and weter are 113. We have a devil statistics of the situation for varous types of hydrogen bonds. Most ofthe asidus, about 78% can make 1 to 3 hydrigen bonds. The asidus, Asp, Gln, Asn andGin, haVe a high ability to make mere hydrogen bonds. The probability of residues, Ala, Leu,Ile, Gin and Gln are are in the α-helix, whereas Val.Leu,Ile, Tyr and Thr have ahalf in the β sheet.
出处
《生物物理学报》
CSCD
北大核心
1994年第1期19-28,共10页
Acta Biophysica Sinica
