四(4-三甲胺苯)卟啉与其抗体相互作用的紫外可见和圆二色谱研究

四(4-三甲胺苯)卟啉与单抗体3B6结合后，有显的增色效应，反映了卟啉与抗体是刚性紧密结合的，抗体的抗原结合部位有芳香族氨基酸存在，并且产生巨大的诱导效应．用紫外(UV)可见和圆二色谱(CD)分析四(4-三甲胺苯)卟啉同抗体的结合，表明(四(4-三甲胺苯)卟啉与单抗体，既有1：1结合又有2：1结合．     

用荧光光谱和紫外-可见差谱研究抗体-卟啉的相互作用

meso-四(α,α,α,α-O-苯乙酰苯)卟啉与其单克隆抗体1F2结合后,产生显著的增色效应,反映了卟啉与抗体之间刚性紧密的结合,在抗体中的抗原结合部位存在芳香族氨基酸.用同步荧光光谱结合荧光猝灭法得到抗体抗原结合部位的芳香族氨基酸主要为色氨酸和酪氨酸,但酪氨酸的残基数要少于色氨酸.卟啉与抗体的结合比为1:1,解离常数(2.084±0.246)×10^-10mol/L,可见卟啉与McAb₁F₂有很高的亲和力.     

一种简易长光程可见紫外、圆二色薄层光谱电化学池

设计了一种简易实用的长光程薄层光谱电化学池,该池以10mm石英比色槽为光学窗,2块5×10×50mm的聚四氟乙烯块为电极支承体,玻碳片为工作电极,且薄层厚度可调。以K_3Fe(CN)_6和L-酪氨酸为工作体系进行光谱和电化学实验表明,该池具有良好的薄层电化学特征。对于水溶液,在大于220nm波长内给出良好的光谱和较快的光谱电化学响应,可方便地用于圆二色谱-电化学研究。     

卟啉作为信号传递介质的紫外可见光谱研究

合成了6种氨基酸水杨醛席夫碱(Sal-AA)：Sal-Gly(甘氨酸)、Sal-Phe(苯丙氨酸)、Sal-Arg(精氨酸)、Sal-Tyr(酪氨酸)、Sal-Met(甲硫氨酸)、Sal-Glu(谷氨酸)及其金属铜配合物。并分别在2种不同介质(三氯甲烷和甲醇)中，与四苯基卟啉TPP进行反应，研究了其紫外可见光谱性质，讨论了卟啉作为人工信号转导体系的传递介质，与氨基酸水杨醛席夫碱铜配合物的反应中，实现信号分子铜离子进一步传递的可能性以及溶剂对该信号传递的影响。结果表明，在三氯甲烷为溶剂时，除了Sal-Met的铜配合物之外，其余均能被TPP夺取而形成Metal TPP。而在以甲醇为溶剂时，只有Sal-Gly的铜配合物能被TPP所夺取。     

抗meso-四(α,α,α,α-O-苯乙酰苯)卟啉抗体的酶学性质研究

利用小分子ｍｅｓｏ－四(α,α,α,α－Ｏ－苯乙酰苯)卟啉作为全抗原免疫小鼠,通过细胞融合等技术制备了单克隆抗体(ＭｃＡｂ)１Ｆ２,利用高效液相色谱(ＨＰＬＣ)、基质辅助激光解吸飞行时间质谱(ＭＡＬＤＩ/ＴＯＦＭＳ)证明纯化得到的单抗是很纯的．ＭｃＡｂ１Ｆ２的保留时间是２．６３ ｍｉｎ,亚型为ＩｇＧ２ａ,相对分子量为１５６ ６７８．８．ＭｃＡｂ １Ｆ２－卟啉复合物形成时,卟啉Ｓｏｒｅｔ带最大吸收峰从４０８ｎｍ红移到４１６ｎｍ,并有增色效应,说明ＭｃＡｂ１Ｆ２－卟啉是刚性且紧密结合．抗体酶稳定性很高,但比活力只有４．６８７ ５ Ｕ/ｍｇ,为天然酶ＨＲＰ的１．８９９%．抗体酶的Ｋｍ＝２０．２９ ｍｍｏｌ/Ｌ,ｋｃａｔ＝３９６．８２ ｍｉｎ－１,ｋｃａｔ/Ｋｍ＝１．９５５ ７×１０４Ｌ·ｍｏｌ－１·ｍｉｎ－１．     

紫外-可见光谱-偏最小二乘法测定渣油四组分含量

用已建立的渣油聚类和识别模型将渣油分为坟渣油、减压渣油和加氢渣油,用紫外－可见光谱－偏最小二乘法（ＵＶ－ＰＬＳ）分别建立了这３种渣油的饱和烃、芳烃、胶质和沥青质四组分测定模型。该方法的测定结果与经典洗脱色谱法（ＥＣ）的结果相吻合。与ＥＣ方法相比,该方法具有快速、操作简单、不需分离,重复性好等特点。     

手性卟啉化合物聚集体与DNA 的相互作用: 电子吸收光谱 和圆二色光谱研究

使用电子吸收光和圆二色(circulardichroism,CD)光谱研究了手性氨基酸卟啉锌配合物(Thr---TPPZN)聚集体与DNA之间的相互作用,这种螺旋结构的手性卟啉聚集体能与DNA结合,L－Thr----TPPZN聚集体与DNA作用量是通过氨基酸残基与DNA的磷酸链形成氢键,结合模式为外部结合,而D----Thr--TPPZN聚集体与DNA作用除了存在以上这种氢键作用之外,卟啉单元还能部分地插入DNA中,与DNA的碱基对形成π-π堆积作用。L--Thr---TPPZN和D--Thr--TPPZn聚集体与DNA结合模式不同是由于L-------Thr----TPPZn聚集体的左手螺旋结构与DNA的右手螺旋结构不匹配,而右手螺旋结构的D--Thr-----TPPZN聚集体能嵌入同样是右手螺旋结构的DNA中。     

手性锌卟啉的圆二色光谱研究

用圆二色光谱（CD）研究了三种新型手性卟啉锌[α,β,α,β－四－[邻（叔丁氧羰L－丙氨酸）氨基苯基]卟啉锌α,β,α,β,－ZnT(o-BocAla)APP1、α,β,α,β-四－[邻（叔丁氧羰L－脯氨酸）氨基苯基]卟啉锌α,β,α,β－ZnT(o-BocPro)APP2和α,β,α,β－甲－[邻（苯甲酰L－谷酰胺）氨基苯基]卟啉锌α,β,α,β－ZnT(o-BenzoylGln)APP3]在CH2Cl2 中的光谱行为,并研究了1作为主体识别手性客体分子氨基酸甲酯前后的光谱,提出了光谱形成机理。     

卟啉试剂与稀土元素显色反应的分光光度法研究（Ⅰ）meso－四（对磺基苯）卟啉（TPPS4）分光光度法测定痕量钇

本文研究了在ｐＨ１１．０的硼砂－ＮａＯＨ缓冲介质中，以Ｈｇ（Ⅱ）作催化剂，在乳化剂（ＯＰ）和溴化十六烷基三甲基铵（ＣＴＭＡＢ）协同作用下，ｍｅｓｏ－四（对磺基苯）卟啉（ＴＰＰＳ４）测定钇（Ⅲ）的显色反应，其摩尔吸光系数ε４１７为５．４６×１０６Ｌ·ｍｏｌ－１·ｃｍ－１，钇浓度在０～０．０３０μｇ／１０ｍＬ内符合比耳定律，在室温下显色迅速，１００倍重稀土不干扰，测定合成稀土混合样品中钇（Ⅲ）含量，回收率为９４％～９８％．     

手性氨基酸卟啉化合物的CD光谱及紫外-可见光谱研究

在合成的手性氨基酸卟啉化合物ThrTPPZn和SerTPPZn(Thr:苏氨酸,Ser:丝氨酸)中,氨基酸残基与卟啉单元相互作用使氨基酸残基的构象相对固定,卟啉化合物在Soret区产生分裂的CD光谱.而在LeuTPPZn中氨基酸残基与卟啉单元的相互作用很弱,卟啉化合物的CD光谱很弱.在室温下,手性氨基酸卟啉化合物对映体的紫外-可见吸收光谱相同,当温度降低时,ThrTPP,SerTPP及其锌配合物在240 nm处的吸收光谱随着温度的降低吸收值减小,在278 K时,L-SerTPP,L-ThrTPP,D-ThrTPPZn 和D-SerTPPZn在275 nm处有强、宽的吸收峰,这是由于在低温下分子的内能减小,氨基酸残基的旋转受到限制,分子内的相互作用增大,羰基与卟啉环之间的共轭增大所致.     

Study on the Determination of Meloxicam by Ultraviolet-Visible Spectrophotometry

Meloxicam is a new non-steroid anti-inflammatory drug (NSAID). In contrast to other NSAIDs currently available,such as piroxicam, tenidap and indomethacin, it appears to have greater inhibitory activity against the inducible isoform of cyclo-oxygenase (COX-2), which is implicated in the inflammatory response,than against the constitutive isoform (COX-1).     

Characterization of the Interactions of Lysozyme with DNA by Surface Plasmon Resonance and Circular Dichroism Spectroscopy

Association with nucleic acid has been recognized as a unique role of lysozyme and may explain why lysozyme was called a killer protein against HIV infection. In the present study, we characterized the interactions of lysozyme and its derived peptides with a biotin-labeled pUC19 plasmid DNA. Real-time detection of the macromolecular interaction was performed using the SPR (surface plasmon resonance) spectroscopy. The SPR sensorgrams were analyzed and the association and dissociation rate constants as well as the dissociation equilibrium constant K _D were, thus, estimated. The results reveal that other than the electrostatic interactions between the basic protein and the nucleotide sequences carrying negative charges, the specific DNA-binding motifs at the N- and C-termini of lysozyme were also involved in the interactions. The nonapeptide RAWVAWRNR (aa 107–115 of lysozyme) reported previously to block HIV-1 viral entrance and replication was also able to bind DNA with its K _D value comparable to that of histones. The possibilities of ligand-binding-induced conformational changes were investigated using the circular dichroism spectroscopy. The CD spectra (200–320 nm) reveal that the conformational changes indeed occur as the spectra of lysozyme–DNA interactions are much less at the major trough region than the sum of individual spectra. The interaction of lysozyme with DNA molecules may interfere with DNA replication, modulate gene expression, and block bacterial and viral infections. These all suggest that human lysozyme may represent part of the innate immune system with a very broad protective spectrum.     

Induced Circular Dichroism and Magnetic Circular Dichroism Spectra of Maleimide and Related Molecules

The induced circular dichroism (ICD) spectra of the inclusion complexes of maleimide, phthalimide, and naphthalene‐2,3‐dicarboximide with β‐ or γ‐cyclodextrin (CDx) have been measured. The structure of the CDx inclusion complexes are interpreted by the signs and shapes of ICD spectra compared with the results of PPP calculations. In maleimide and naphthalene‐2,3‐dicarboximide, the ICD spectra of the β‐CDx inclusion complex are very similar to those of the γ‐CDx inclusion complex in spite of the differences in dimensions between the cavity of β‐CDx and that of γ‐CDx. In phthalimide, the ICD spectra of the β‐CDx inclusion complex are very different from those of the γ‐CDx inclusion complex. The split‐type ICD bands at 220–235 nm show that the dimer of phthalimide is formed in the presence of β‐CDx.     

Magnetic Circular Dichroism and Induced Circular Dichroism Spectra of N‐Bromophthalimide

The magnetic circular dichroism (MCD), induced circular dichroism (ICD) spectra, and the absorption spectra of N‐bromophthalimide have been measured. The ICD spectrum of the β‐cyclodextrin complex with N‐bromophthalimide is also reported. The absorption bands of N‐bromophthalimide are assigned.     

天花粉蛋白二级结构的圆二色性研究

本文报告了室温条件下在185—330nm波长范围内天花粉蛋白的CD谱测定的结果。利用205—240nm区间的CD谱,借助参考CD谱用最小二乘拟合的方法,计算得天花粉蛋白中α螺旋平均含量为24％,β折叠含量为30％,无序构象含量为46％。     

Electronic Circular Dichroism Spectra of DNA Quadruple Helices Studied by Molecular Dynamics Simulations and Excitonic Calculations including Charge Transfer States

We here investigate the Electronic Circular Dichroism (ECD) Spectra of two representative Guanine-rich sequences folded in a Quadruple helix (GQ), by using a recently developed fragment diabatisation based excitonic model (FrDEx). FrDEx can include charge transfer (CT) excited states and consider the effect of the surrounding monomers on the local excitations (LEs). When applied to different structures generated by molecular dynamics simulations on a fragment of the human telomeric sequence (Tel21/22), FrDEx provides spectra fully consistent with the experimental one and in good agreement with that provided by quantum mechanical (QM) method used for its parametrization, i.e., TD-M05-2X. We show that the ECD spectrum is moderately sensitive to the conformation adopted by the bases of the loops and more significantly to the thermal fluctuations of the Guanine tetrads. In particular, we show how changes in the overlap of the tetrads modulate the intensity of the ECD signal. We illustrate how this correlates with changes in the character of the excitonic states at the bottom of the La and Lb bands, with larger LE and CT involvement of bases that are more closely stacked. As an additional test, we utilised FrDEx to compute the ECD spectrum of the monomeric and dimeric forms of a GQ forming sequence {"type":"entrez-nucleotide","attrs":{"text":"T30695","term_id":"612793"}}T30695 (5′TGGGTGGGTGGGTGGG3′), i.e., a system containing up to 24 Guanine bases, and demonstrated the satisfactory reproduction of the experimental and QM reference results. This study provides new insights on the effects modulating the ECD spectra of GQs and, more generally, further validates FrDEx as an effective tool to predict and assign the spectra of closely stacked multichromophore systems.