共查询到18条相似文献,搜索用时 171 毫秒
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第一个生物大分子——溶菌酶的激光拉曼光谱发表于1968年。两年后R.C.Lord等用浓溶菌酶水溶液实验,对其大部分拉曼谱带作了指认。1970年Rimai等人发表了胡萝卜素、番茄红素、番茄组织和视网膜中视蛋白的共振拉曼光谱。随后十年,拉曼光谱在生物学领域中应用发展极其迅速, 相似文献
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拉曼光谱分析技术在细胞生物学研究中的应用进展 总被引:1,自引:0,他引:1
细胞是生物体结构和功能的基本单位,自被发现以来新的研究方法不断涌现。单细胞拉曼光谱能提供细胞内核酸、蛋白质、脂质含量等大量信息,可在不损伤细胞的条件下实时动态地监测细胞分子结构变化,亦可获得细胞的“分子指纹”,具有敏感性高、实时检测、活样品不需固定或染色、不损伤细胞等众多特点。近年来国内外研究者将拉曼光谱应用于细胞药物处理、细胞水平疾病诊断、单细胞生命活动监测、亚细胞结构等研究,取得了不同程度的进展。随着研究的深入,拉曼光谱分析技术必将在干细胞,癌症研究、细胞分选、药物筛选等领域大有作为。 相似文献
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Dispersive Raman spectroscopy allows the identification and quantification of melanin types 下载免费PDF全文
Melanins are the most prevalent pigments in animals and are involved in visual communication by producing colored traits that often evolve as intraspecific signals of quality. Identifying and quantifying melanins are therefore essential to understand the function and evolution of melanin‐based signals. However, the analysis of melanins is difficult due to their insolubility and the lack of simple methods that allow the identification of their chemical forms. We recently proposed the use of Raman spectroscopy as a simple, noninvasive technique that can be used to identify and quantify melanins in feathers and hairs. Contrarily, other authors later stated that melanins are characterized by a lack of defined Raman signals. Here, we use confocal Raman microscopy to confirm previous analyses showing that the two main chemical forms of melanins (eumelanin and pheomelanin) exhibit distinct Raman signal and compare different excitation wavelengths to analyze synthetic pheomelanin and natural melanins in feathers of different species of birds. Our analyses indicate that only laser excitation wavelengths below 1064 nm are useful for the analysis of melanins by Raman spectroscopy, and only 780‐nm laser in the case of melanins in feathers. These findings show that the capacity of Raman spectroscopy to distinguish different chemical forms of melanins depends on laser power and integration time. As a consequence, Raman spectroscopy should be applied after preliminar analyses using a range of these parameters, especially in fragile biological tissues such as feathers. 相似文献
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We have recently applied surface-enhanced Raman spectroscopy (SERS) for blood plasma analysis for non-invasive nasopharyngeal cancer detection and obtained good preliminary results. The aim of this study was to develop a more robust SERS spectroscopy based blood plasma analysis method for non-invasive gastric cancer detection. The effect of different laser polarizations (non-polarized, linear-polarized, right-handed circularly polarized, and left-handed circularly polarized) on blood plasma SERS spectroscopy was explored for the first time. Silver nanoparticles as the SERS-substrate were directly mixed with blood plasma to enhance the Raman scattering of various biomolecular constituents. High quality SERS spectra were obtained using a fiber optic probe and a dispersive type near infrared Raman system. Blood plasma samples from gastric cancer patients (n=32) and healthy subjects (n=33) were analyzed. The diagnostic performance for differentiating gastric cancer plasma from normal plasma was evaluated. Principal component analysis combined with linear discriminant analysis (LDA) of the obtained spectral data was used to develop diagnostic algorithms. Classification results obtained from cross-validation of the LDA model based on the four spectral data sets of different laser polarizations demonstrated different diagnostic sensitivities and specificities: 71.9% and 72.7% for non-polarized laser excitation, 75% and 87.9% for linear-polarized laser excitation, 81.3% and 78.8% for right-handed circularly polarized laser excitation, 100% and 97% for left-handed circularly polarized laser excitation. The results from this exploratory study demonstrated that plasma SERS spectroscopy with left-handed circularly polarized laser excitation has great promise of becoming a clinically useful diagnostic tool for non-invasive gastric cancer detection. 相似文献
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Studies of native chromatins and of isolated nucleosomes (from calf thymus) show that the DNA is in the B form or modified B form. This was determined by Raman spectroscopy of chromatins, of nucleosomes (from calf thymus) and of DNA fibres and directly correlated with X-ray diffraction studies. The Raman spectra of three forms of DNA (A, B and C) have been characterized in fibres both by X-ray diffraction and Raman spectroscopy on the same sample. In particular, the Raman spectrum of the C form of DNA is characterized by a band of about 870 cm(-1). For the first time, chromatins of different origins with increasing content of non-histone proteins have been investigated by Raman spectroscopy. The site of interaction of the non-histone proteins appears to involve the N7 position of guanine while the histone core does not interact at this site. It is proposed that the mechanism of specific recognition in chromatin involves the large groove. 相似文献
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Structural effects of binding the intercalating drug ethidium bromide (EtBr) to 160 base pair (bp) fragments of nucleosomal calf thymus DNA have been probed by the method of Raman difference spectroscopy. With the use of a near-infrared (NIR) laser source to excite the Raman spectrum at 752 nm, vibrational signatures of both the EtBr intercalant and DNA target have been identified in spectra of the drug-DNA complexes. Analysis of the results obtained on complexes consisting of 1 EtBr bound/10 bp leads to the following conclusions: (i) Raman markers diagnostic of DNA phosphodiester conformation are converted from the B type to the A type with EtBr binding, commensurate with the proportion of ethidium-bound nucleotides in the complex. (ii) Ethidium binding converts deoxynucleoside sugar puckers from the C2'-endo to the C3'-endo conformation, also consistent with binding stoichiometry. Both pyrimidine and purine deoxynucleoside sugar puckers are perturbed by the phenanthridinium ring intercalation. (iii) Phenanthridinium insertion between bases is accomplished with no apparent change in hypochromicities of purine or pyrimidine Raman markers, indicating that base-phenanthridinium interactions provide compensatory hypochromic effects. (iv) Novel Raman markers of helix unwinding have been identified and assigned primarily to methylene deformation modes of the deoxyribosyl C2'H(2) and C5'H(2) groups. The present study provides new insights into drug-DNA recognition in solution and demonstrates the feasibility of NIR-Raman spectroscopy for structural studies of highly chromophoric DNA complexes. 相似文献
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Raman spectroscopy is a spectroscopic analysis technique that enables rapid qualitative and quantitative detection based on inelastic collision and Raman scattering intensity. This review detailed the generation principle, instrument composition, influencing factors, and common classifications of Raman spectrum. Furthermore, it summarized and forecast the research progress of Raman spectroscopy in the field of drug analysis simultaneously over the past decade, including the identification of active pharmaceutical ingredients (APIs), qualitative and quantitative studies of pharmaceutical preparations, detection of illicit drugs, the identification of Chinese herbal medicines, and the combination with other technologies. The development of Raman spectroscopy in other fields is additionally summarized. 相似文献
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Christoph Krafft Anuradha A. Ramoji Christiane Bielecki Nadine Vogler Tobias Meyer Denis Akimov Petra Rösch Michael Schmitt Benjamin Dietzek Iver Petersen Andreas Stallmach Jürgen Popp 《Journal of biophotonics》2009,2(5):303-312
An experimental evaluation of the information content of two complimentary techniques, linear Raman and coherent anti‐Stokes Raman scattering (CARS) microscopy, is presented. CARS is a nonlinear variant of Raman spectroscopy that enables rapid acquisition of images within seconds in combination with laser scanning microscopes. CARS images were recorded from thin colon tissue sections at 2850, 1660, 1450 and 1000 cm–1 and compared with Raman images. Raman images were obtained from univariate and multivariate (k‐means clustering) methods, whereas all CARS images represent univariate results. Variances within tissue sections could be visualized in chemical maps of CARS and Raman images. However, identification of tissue types and characterization of variances between different tissue sections were only possible by analysis of cluster mean spectra, obtained from k‐means cluster analysis. This first comparison establishes the foundation for further development of the CARS technology to assess tissue. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim) 相似文献
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The lambda repressor provides a model system for biophysical studies of DNA recognition by the helix-turn-helix motif. We describe laser Raman studies of the lambda operator sites OL1 and OR3 and their interaction with the DNA-binding domain of lambda repressor (residues 1-102). Raman spectra of the two DNA sites exhibit significant differences attributable to interstrand purine-purine steps that differ in the two oligonucleotides. Remarkably, the conformation of each operator is significantly and specifically altered by repressor binding. Protein recognition, which involves hydrogen-bond formation and hydrophobic contacts in the major groove, induces subtle changes in DNA Raman bands of interacting groups. These include (i) site-specific perturbations to backbone phosphodiester geometry at AT-rich domains, (ii) hydrophobic interaction at thymine 5CH3 groups, (iii) hydrogen bonding to guanine 7N and 6C = O acceptors, and (iv) alterations in sugar pucker within the C2'-endo (B-DNA) family. These perturbations differ between aqueous OL1 and OR3 complexes of repressor, indicating that protein binding in solution determines the precise DNA conformation. The overall structure of the lambda domain is not greatly perturbed by binding to either OL1 or OR3, in accord with X-ray studies of other complexes. However, Raman markers indicate a change in hydrogen bonding of the OH group of tyrosine-22, which is a hydrogen-bond acceptor in the absence of DNA but a combined donor and acceptor in the OL1 complex; yet, Y22 hydrogen bonding is not altered in forming the OR3 complex. The present results demonstrate qualitatively different and distinguishable modes of interaction of the lambda repressor DNA-binding domain with operators OL1 and OR3 in solution. This application of laser Raman spectroscopy to a well-characterized system provides a prototype for future Raman studies of other DNA-binding motifs under physiological conditions. 相似文献
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作者用激光喇曼光谱法分析半乳糖导致大白鼠晶状体混浊过程中构象的变化。通过SPEX 1403型激光喇曼光谱仪得到了正常及不同混浊度晶状体的喇曼光谱。结果表明晶状体可溶性蛋白质二级结构的光谱未见异常,其残基酪氨酸及色氨酸微环境起了变化。随着晶状体混浊度的增加,SH谱峰强度变小而S-S键谱峰增强,同时观察到荧光背景逐渐加强。经分析认为晶状体混浊是与蛋白质分子的聚集有关。 相似文献