活性中心

The affection of the autolysis of the peptide near active site on trypsin activity has also been analysed.

我们还分析了EPT活性中心部位附近肽键的自溶对猪胰蛋白酶的活性的影响。

Essential amino acid residues in diphtheria toxin catalytic domain were determined by quantum chemistry calculation and the enzymatic activities of mutant in the active-site were tested in order to provide high effective cytotoxin for target anticancer drugs.

通过量子化学计算确定白喉毒素分子催化区活性中心的关键氨基酸残基，评价其取代后的酶活性的改变，为导向性抗癌药物研究提供高效杀伤细胞工具。

The results indicate that the three metal complexes could catalyze the disproportionation of the superoxide anion free radical O2(superscript -, and could be used as the active center model complexes of SOD.

结果表明，3种金属配合物均有一定的催化歧化超氧阴离子自由基O2(上-活性，均可被称作超氧化物歧化酶活性中心的模拟配合物。

A series homopolyme of ethylene synthesised by metallocene catalyst was analyzed by the high temperature gelatin permeation chromatography. The results showed that the molecular weight distribution changed not too much when the ratio of Al/Ti ranging between 1000 and 4000, while the molecular weight distributed increased from 2.48 to 2.81 when the ratio ranging between 4000 and 7000; catalyst D had the lowest activity to be used as asymmetric metallocene catalyst; the curve of molecular weight moved much to the left with the increases of temperature and two active centres appeared when the temperature is 70℃.

通过高温凝胶渗透色谱对茂金属催化合成的一系列乙烯均聚物进行了分析，可以看出Al/Ti比从1000变到4000时，分子量分布曲线图变化不大，而从4000变到7000时，变化相当大，分布宽度从2.48增至2.81；催化剂D的活性最小，可作为非对称性茂系金属催化剂；该聚合体系分子量的大小受聚合温度的影响很明显，随温度的升高，分子量分布曲线图向左发生很大位移，在聚合温度为70℃时存在两个活性相当的活性中心。

For low molar ratios of Al/Zr, a hypsochromic shift of the initial catalyst absorption band, corresponding to the monomethylation of the catalyst, was observed. Further addition of AlEt2Cl was accompanied by a continuous bathochromic shift of the maximal wavelength corresponding to the formation of more dissociated ionic active species. Then, there would be a coordination of monomer to the ionic active species.

结果表明，无论是AlEt_2Cl还是MAO，少量的助催化剂首先使催化剂发生单烷基化反应，主催化剂金属中心的最大吸收峰波长发生蓝移，而当助催化剂量进一步增加时，金属中心的最大吸收峰波长红移，单烷基取代的催化剂被大量的助催化剂夺去电子成为缺电子的阳离子活性中心，以便烯烃单体的配位插入。

Our purpose is simulating the catalytical action of enzyme in biologic system, so we can directly investigate the factors relating to the functions of enzyme by studying the catalyzing behavior of model molecules imitating enzyme\'s functions. And it is a base of synthesizing high performance model enzyme.

从得到的实验数据我们可以看出：锌是酯水解反应的活性中心；并且金属中心相同时，配位数相同的配合物，结构越简单，其催化酯水解效果越好；含有配位不饱和金属中心的锌配合物表现出更好的催化效果；配合物中咪唑基团的存在可有效的增强这个配合物催化酯水解的效果。

Because of the bonded crown ring the catalytic activity of complexes can be improved and the induce period of the oxidation for p-xylene to p-toluic acid was shortened from～ 10h to 0.5～5h, the fashion and position of the bonded crown ring as well as the distance between the crown ring and activity center have distinct influence on the catalytic activity of complexes.

结果表明：1。键连的冠醚环均能显著提高催化活性，并大大缩短反应诱导期5-10h，使TOF从21～60提高到152～222，约增加了5～7倍；冠环的键连方式和部位以及与活性中心的距离对催化活性影响明显；2。

Its amino acid sequence has nine conserved blocks of Glycosyl hydrolases family 35, including an active site Glu210 of proton donor, but lacking another active site Glu279 of nucleophile.

Bin2a的氨基酸序列中包括Glycosyl hydrolases family 35家族中的9段相对保守的序列，其中包括210位的活性中心Glu，但是缺少另外一个活性中心，279位的Glu。

The full-length cdna of bin2a is 2606bp, encoding 637 amino acid. its amino acid sequence has nine conserved blocks of glycosyl hydrolases family 35, including an active site glu210 of proton donor, but lacking another active site glu279 of nucleophile.

bin2a的全长cdna为2606bp，编码×××个氨基酸。bin2a的氨基酸序列中包括glycosyl hydrolases family ×××家族中的9段相对保守的序列，其中包括210位的活性中心glu，但是缺少另外一个活性中心，279位的glu。

The results of the surface composition of the sample washed with and without aqueous ammonia show that most of the impurities which consists of C, B, O elenents mainly can be removed by washing with aqueous ammonia.

测量了改变KBH〓/Ni〓制备的样品的组成、粒径和催化活性，发现当KBH〓Ni〓＞2时催化活性逐渐下降，这是由于随KBH〓/Ni〓的增加颗粒的粒径增大，从而导致活性中心的数量下降所致。

Breath, muscle contraction of the buttocks; arch body, as far as possible to hold his head, right leg straight towards the ceiling (peg-leg knee in order to avoid muscle tension).

呼气，收缩臀部肌肉；拱起身体，尽量抬起头来，右腿伸直朝向天花板（膝微屈，以避免肌肉紧张）。

The cost of moving grain food products was unchanged from May, but year over year are up 8%.

粮食产品的运输费用与5月份相比没有变化，但却比去年同期高8％。