化合物（Et_4N）_2［Pd_2（mp）_2（μ－mpH）_2］的NMR研究

采用１Ｈ－１ＨＣＯＳＹ，ＨＭＱＣ、ＨＭＢＣ等２ＤＮＭＲ技术对化合物（Ｅｔ４Ｎ）２［Ｐｄ２（ｍｐ）２（μ－ｍｐＨ）２］进行１Ｈ、１３ＣＮＭＲ谱数据分析与归属．表明它在ＤＭＳＯ溶液中仍保持原有固体状态的分子结构．     

一类修正的Navier—Stokes方程组Neumann边值问题的弱解

讨论一类修正的Ｎａｖｉｅｒ－Ｓｔｏｋｅｓ型方程组Ｎｅｕｍａｎｎ边值问题的可解性及解的性质。     

蛇肌果糖1,6-二磷酸酯酶的限制性酶解

蛇肌果糖1.6-二磷酸酯酶被枯草杆菌蛋白酶或胰蛋白酶限制性酶解,可分别产生29000和7000或32000和4000的肽段。酶解产物在pH7.5和pH9.2分别有2倍和4—5倍的激活,pH7.5的激活作用,仅可用无机磷测活法观察到。5′AMP对该产物的别构抑制作用部分或全部丧失。本文与文献[1]的结果使我们提出了天然状态的蛇肌酶的催化部位的结构是不完善的看法。被限制性酶解的蛇肌酶受6-磷酸果糖激活,同时又受6-磷酸葡萄糖酸,6-磷酸葡萄糖和还原型辅酶Ⅱ的抑制。因此限制性酶解作用可能在蛇肌中有一定生理功能。     

ARGINYL-tRNA SYNTHETASE FROM Escherichia coli AFFINITY LABELING WITH 3''''-OXIDIZED tRNA~(Arg)

The covalent modification of E. coli arginyl-tRNA synthetase by the 2',3'-dialdehydederivative of tRNA~(Arg) (tRNA_(ox)~(Arg)) resulted in the complete inactivation of the ATP-PPi ex-change and aminoacylation activities of the enzyme. Sodium dodecyl sulfate polyacrylamide gelelectrophoresis of the ArgRS-tRNA_(ox)~(Arg) covalent complexes indicated that two bands simulta-neously appeared on the gel parallel with inactivation corresponding to different higher mo-lecular weights. This result was different from that of the other aminoacyl-tRNA synthetaselabeling systems as previously reported. Upon the ribonuclease treatment of the modifiedArgRS, less than 15% of both the initial ATP-PPi exchange and aminocylation activities wererecovered. During the whole process of labeling and RNase treatment, the two activities ofthe enzyme were closely associated.     

CHEMICAL MODIFICATION OF SULFHYDRYL GROUPS OF E.coli LEUCYL-tRNA SYNTHE-TASE AND SEQUENCING OF [~(14)C]NEM-LABELED PEPTIDES

The chemical modification of the sulfhydryl groups of E. coli Leucyl--tRNA synthetase(LeuRS) by DTNB, NEM and IAA resulted in a time-dependent loss of both amino-acid acti-vation and aminoacylation activities in parallel. The second-order reaction constants of DTNB,NEM and IAA were 1700, 150 and 0.46 mol/L~(-1) min~(-1) respectively. Chemical stoichiometryshowed that only one sulfhydryl group of LeuRS was essential for both activities. Substratesleucine and Leu-AMP protected the active sulfhydryl group from modification, suggestingthat the modified sulfhydryl group is located in or near the active site region responsiblefor amino-acid activation. [~(14)C]NEM--labeled LeuRS was subjected to tryptic digestion, andpeptides were separated and sequenced. 179 Cys~*-Asp-Thr-Leu182 was identified as the major[~(14)C]NEM-labeled site in LeuRS. This result is consistent with the previous observationthat the region for Leu--AMP formation was located at the N--terminal part of LeuRS.     

Cu2+与烟草多酚氧化酶相互作用研究

本文通过酶活性测定,荧光光谱和紫外光谱研究了外加Cu2+与烟草多酚氧化酶(简称PPO)的相互作用。结果表明,微量铜的加入能增加酶的活性,犤Cu2+犦/犤PPO犦为0.20左右时酶活性最大,犤Cu2+犦/犤PPO犦为0.91时,Cu2+开始表现出对PPO活性的抑制;Cu2+对PPO内源荧光的猝灭机制属于形成络合物所引起的静态猝灭,猝灭常数Ksv为8.0375×103L·mol-1;Cu2+的加入使PPO蛋白质分子构象发生变化,α-螺旋含量增加,多肽链及Trp和Tyr残基的芳杂环进一步向分子内收缩,疏水基团之间的疏水作用增强。     

Y2O2S：Eu，Ti，Mg红色长余辉的温度依赖

实际应用中在低温下一些长余辉材料不能正带工作，因此需要研究长余辉材料的温度依赖特性。用固相反应法合成了Y2O2S：Eu，Ti，Mg，测量了其余辉发射谱和热释光曲线，研究Y2O2S：Eu，Ti，Mg在140～300K和290～350K温区的长余辉发光的发射光谱和衰减曲线的温度依赖。当温度低于其热释光曲线起始点230K时，其余辉的发射光谱强度较弱。随温度增加，其余辉的发射光谱强度随温度增强。300K后，其余辉衰减时间随温度变快。Y2O2S：Eu，Ti，Mg长余辉的温度依赖行为与其热释光曲线密切相关，并通过长余辉机制对其进行了分析和讨论。     

ω-氨基酸缩聚反应动力学研究

前曾报导9-氨基壬酸的缩聚,从开始到反应程度p增加到99％左右时止,均遵循二级反应。在这以后,由于体系粘稠的影响,迅速转为三级反应。本文报导在6-氨基己酸和11-氨基十一酸缩聚时,也出现同样现象,即在p逐渐到高于99％左右时,反应从二级转变为三级。可以说这一现象是AB型单体聚酰胺化的一般规律,从而澄清了文献中对这一问题的不同论点。     

含蒽醌结构新型共聚酯染料的合成及性能

以溶液聚合法合成了以１,５－二－β－羟乙醚基蒽醌为染料单体的新型共取酯染料,通过紫外－可见、核磁共振、热重等方法对聚合物性能进行表征,将其作为色母在毛细管流变仪上对聚酯纤维进行共混染色,并测定其光宾度。     

杯芳烃的配位化学研究 Ⅰ.对叔丁基杯芳烃对铜的萃取

新一代大环化合物杯芳烃(calixarcne)的研究已引起广泛的兴趣,它是由酚环和亚甲基组成的环多聚体,其结构呈杯状.杯底OH及杯盖R基可被各种基团取代,在其环形结构中具有适当体积的洞穴,在此空穴中能容纳客体而形成主客体配合物,可模拟酶催化的初始过程,在催化及分析分离等方面也有广泛的应用.但杯芳烃的配位化学研究很少,本文首先合成了对叔丁基杯[4]芳烃、对叔丁基杯[6]芳烃及对叔了基杯[8]芳烃(分别简称杯[4]、杯[6]及杯[8]),研究它们对铜的萃取,并探讨了萃取机理.