不同pH条件下细菌视紫红质的共振拉曼光谱研究

本实验测定了不同pH条件下嗜盐菌紫膜中细菌视紫红质(bR)的共振拉曼光谱.13-顺式视黄醛生色团的特征峰1187cm~(-1)和全反式、13-顺式共有的特征峰1200cm~(-1)带强度之比I_(1187)/I_(1200)在pH1.0-8.9之间约为0.76,而pH高于8.9为0.97.pH3.0-9.0时C=NH~ 振动峰为1640-1642cm~(-1),pH9.4以上为1642-1644cm~(-1),pH9.2附近变化最大,pH3.0以下低于1640cm~(-1).酸性和弱碱性范围时,19-CH_3和20-CH_3的面内变形振动与面外变形振动相互重叠,碱性范围分为双峰.并讨论了对结构及其稳定性的影响.     

拉曼光谱单细胞分选技术研究进展

拉曼激活细胞分选(Raman-activated cell sorting,RACS)作为一种无标记、无损、高通量的单细胞分选技术,对于原位研究复杂细胞群体中单个细胞的个体性和异质性意义重大。本文对四种不同RACS集成技术的原理、工作方式、发展现状进行了阐述,分析基于拉曼光谱单细胞分选技术的应用前景,探讨提高单细胞分选速率的研究方向。     

表面增强拉曼光谱技术在微生物鉴定中的应用进展

拉曼光谱自20世纪20年代被发现以来,经过近90年的发展,产生了许多分支。其中表面增强拉曼光谱是利用被测物质与粗糙金属表面的相互作用来提高拉曼光谱的信噪比,从而得到敏感度和精确度更高的图谱,可以将样品在不经过预处理的情况下对其进行快速检测。本文综述了表面增强拉曼光谱技术的原理、分类及鉴定特点,总结了该技术在食品、化学、医药、工业、病原等微生物学科的临床应用,进一步阐述了研究该技术的必要性和应用前景,旨在为从事该领域的科研人员提供参考依据。     

拉曼光谱技术在微生物学中的应用

拉曼光谱具有快速、灵敏、无损、实时监测等显著特点,在微生物学领域得到广泛应用。分别介绍共焦显微拉曼光谱、共振拉曼光谱、表面增强拉曼光谱、拉曼成像、相干反斯托克斯拉曼光谱、激光镊子拉曼光谱和Raman-FISH的原理和特点,并重点总结和分析不同拉曼光谱技术在微生物的结构、化学组成,以及代谢过程等相关研究中的应用优势。合理利用这些技术在基础微生物、发酵微生物和微生物诊断等方面具有潜在的应用价值。     

激光拉曼光谱技术在生物分子DNA研究中的应用和进展

激光技术的兴起使拉曼光谱成为激光分析中最活跃的研究领域之一,已被广泛地用于物质成分的分析和分子结构的鉴定。本文综述了拉曼技术在DNA研究中近年来的最新进展,包括：DNA的常规拉曼光谱分析;DNA的激光共振拉曼光谱分析;DNA在金属表面或电极上吸附行为的表面增强拉曼光谱研究;DNA的傅立叶变换拉曼光谱研究等。并对拉曼光谱技术在DNA等生物大分子领域中的研究前景做了进一步的展望。     

拉曼光谱检测微生物的研究方法和进展北大核心

快速准确地识别和鉴定微生物对于环境科、食品质量以及医学诊断等领域研究至关重要。拉曼光谱(Raman spectroscopy)已经被证明是一种能够实现微生物快速诊断的新技术,在提供微生物指纹图谱信息的同时,能够快速、非标记、无创、敏感地在固体和液体环境中实现微生物单细胞水平的检测。本文简单介绍了拉曼光谱的基本概念和原理,重点综述了拉曼光谱微生物检测应用中的样品处理方法及光谱数据处理方法。除此之外,本文概括了拉曼光谱在细菌、病毒和真菌中的应用,其中单独概括了拉曼在细菌快速鉴定和抗生素药敏检测中的应用。最后,本文阐述了拉曼光谱在微生物检测中的挑战和展望。     

抗癌药物ADM与DNA相互作用的紫外共振拉曼光谱的研究

用紫外共振拉曼光谱研究了ＡＤＭ与小牛胸腺ＤＮＡ相互作用,分析表明：ＡＤＭ插入ＤＮＡ的ＧＣ－ＣＧ位置,ＡＤＭ与ＤＮＡ之间的主要相互作用是蒽环π电子与碱基Ｇ和Ｃ的π电子形成的π－π电子相互作用,并通过碱基Ｇ,Ｃ的ＮＨ２的氮的孤对Ｐ电子与ＡＤＭ的π－Ｐ电子相互作用以及ＡＤＭ和ＤＮＡ碱基Ｇ,Ｃ和ＰＯ２之间形成的氢键使相互作用加强;ＡＤＭ插入ＤＮＡ使其构象产生一定变化,但未破坏ＤＮＡ碱基对间的氢键。     

激光拉曼光谱在蛋白质构象研究中的应用和进展

激光拉曼光谱法被公认为是研究生物大分子的结构、动力学和功能的有效方法。近年来拉曼光谱在蛋白质构象研究中的最新进展,涉及到拉曼光谱在非折叠蛋白质、蛋白质装配的特征描述,拉曼晶体学在实时监控蛋白质单晶中化学变化等方面的应用。另外,介绍了蛋白质拉曼光谱分析在生物技术中的应用现状。并对拉曼光谱技术在蛋白质等生物大分子领域中的研究前景做了进一步的展望。     

光镊捕获的单个解冻人血红细胞的拉曼光谱研究

红细胞的冰冻与解冻的实施为血液的长期保存提供了有效的方法。在过去的几十年中,红细胞冻存有过数种方法,其中高甘油冻存法比较普遍,因而用此方法保存红细胞是否对红细胞产生了影响及产生了什么影响是值得研究的。作者利用激光光镊拉曼光谱系统,通过拉曼光谱对冻存人血红细胞进行研究;结果显示,红细胞冻存前后的拉曼光谱有一定的变化,解冻提取后也产生了一定的变化,这些变化主要体现在对应拉曼光谱的位置和强度上。研究结果对进一步研究红细胞的冻存具有一定的参考价值。     

皮肤组织显微共聚焦拉曼光谱成像研究

显微共聚焦拉曼光谱成像技术(Confocal Raman Microspectroscopy Imaging,CRMI)能够对样品微区进行精确无损的拉曼光谱分析和光谱图像扫描,提供生物样品的无损高分辨光学信息。本项研究工作,利用CRMI技术实验获取了正常人体离体皮肤组织的拉曼光谱特征,并结合典型特征峰的扫描图像,探讨了脂类、蛋白质等成分在皮肤真皮层的分布特点。实验发现皮肤组织真皮层内胶原蛋白的拉曼特征峰1 248 cm-1强度及其空间分布尤为突出,这一实验结果与组织学中胶原纤维占真皮结缔组织95%的事实相符。实验结果显示,CRMI技术能够全面诠释生物组织内部生化组成与分布信息,在实验描述皮肤组织病理变化的分子生物学机制方面具有广阔的应用前景。     

Confocal Raman microscopy on single living young and old erythrocytes

Raman confocal microscopy, including the techniques of point Raman spectra, line mapping, 2D mapping, and time-dependent spectrum monitoring performed with 514.5 nm excitation light, was used in a comparative study on the distribution and oxidation states of hemoglobin (Hb) in young and old mature erythrocytes. It is demonstrated that in contrast to the homogeneous distribution of the Hb in young cells, there are more Hb distribution around the cell membrane in old erythrocyte. The proteins exhibit some extent of aggregation and conformational change, present less ability of oxidation, and lower oxygenation speed than the Hb in young erythrocytes. Our results also provide the first direct evidence of some intermediate oxygenated states of Hb between the two fully oxygenated (R) and deoxygenated (T) states in living erythrocyte, and give detail information about the conformational change of the intracellular Hb with time during the reoxygenation process. (c) 2008 Wiley Periodicals, Inc. Biopolymers 89: 951-959, 2008.This article was originally published online as an accepted preprint. The "Published Online" date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com.     

Low frequency resonance Raman spectra of isolated alpha and beta subunits of hemoglobin and their deuterated analogues

In an attempt to gain further insight into the nature of the low frequency vibrational modes of hemoglobin and its isolated subunits, a comprehensive study of several different isotopically labeled analogues has been undertaken and is reported herein. Specifically, the resonance Raman spectra, between 200 and 500 cm(-1), are reported for the deoxy and ligated (CO and O2) forms of the isolated alpha and beta subunits containing the natural abundance or various deuterated analogues of protoheme. The deuterated protoheme analogues studied include the 1,3,5,8-C2H3-protoheme (d12- protoheme), the 1,3-C2H3-protoheme (1,3-d6-protoheme), the 5,8-C2H3-protoheme (5,8-d6-protoheme), and the meso-C2H4-protoheme (d4-protoheme). The entire set of acquired spectra has been analyzed using a deconvolution procedure to help correlate the shifted modes with their counterparts in the spectra of the native forms. Interestingly, modes previously associated with so-called vinyl bending modes or propionate deformation modes are shown to be quite sensitive to deuteration of the peripheral methyl groups of the macrocycle, shifting by up to 12-15 cm(-1), revealing their complex nature. Of special interest is the fact that shifts observed for the 1,3-d6- and 5,8-d6-protoheme analogues confirm the fact that certain modes are associated with a given portion of the macrocycle; i.e., only certain modes shift upon deuteration of the 1 and 3 methyl groups, while others shift upon deuteration of the 5 and 8 methyl groups. Compared with the spectra previously reported for the corresponding myoglobin derivatives, the data reported here reveal the appearance of several additional features that imply splitting of modes associated with the propionate groups or that are indicative of greater distortion of the heme prosthetic groups.     

拉曼光谱在皮肤领域的研究进展

拉曼光谱是一种新型的光学检测技术,常用于材料鉴定。近年来,随着无创检测需求的增加,拉曼光谱逐渐应用于疾病诊断、物质鉴别等生物领域。综述了拉曼光谱在皮肤领域的研究进展,及其对皮肤组织成分鉴别和皮肤疾病诊断的价值,以期推动拉曼光谱广泛应用于皮肤病学的机理研究和临床诊断。     

Effect of pH on molecular constitution and distribution of hemoglobin in living erythrocyte

The molecular constitution of in situ hemoglobin (Hb) and their distribution in living erythrocyte were investigated versus pH using the technique of confocal Raman microscopy. Both Raman point spectra and line mapping measurements were performed on living erythrocytes in suspensions with pH values from 4.82 to 9.70. It was found that the Hb inside a living erythrocyte would dissociate into monomer/dimer when the cells are in low and high pH environments. In contrast to the homogeneous distribution of the Hbs in the cells in neutral suspension, there are more Hbs distributing around the cell membrane or binding to the membrane as pH increases. While in low pH, as the cell become spherical, most of the Hbs distribute to the central part of the cell. In summary, our investigation suggests that the variation of the external pH not only brings changes in the morphology and membrane structure of an erythrocyte, but also affects the constitution and distribution of its intracellular Hbs, thereby the flexibility of the cell membrane and the oxygenation ability of the Hb. © 2009 Wiley Periodicals, Inc. Biopolymers 93: 348–354, 2010. This article was originally published online as an accepted preprint. The “Published Online” date corresponds to the preprint version. You can request a copy of the preprint by emailing the Biopolymers editorial office at biopolymers@wiley.com     

卵巢癌患者血清的拉曼光谱研究初探

目的:探究拉曼光谱技术应用于卵巢癌研究的可能性。方法:收集卵巢癌患者血清及健康人血清各20例,用激光共聚焦显微拉曼光谱仪进行检测。结果:两组血清的平均拉曼光谱形态和谱峰基本相似,但在约1010、1158、1283、1520、1646、2307和2661cm-17个拉曼频移附近,卵巢癌患者血清的拉曼光谱谱峰强度明显低于健康对照组,而在其余大部分波段,卵巢癌患者血清的拉曼光谱强度均高于健康对照组。结论:拉曼光谱技术可以初步区分卵巢癌及健康人血清,值得进一步研究和探讨其临床应用价值。     

Assignment of the 1511 cm(-1) UV resonance Raman marker band of hemoglobin to tryptophan

New UV resonance Raman (UVRR) data provide convincing evidence that a characteristic 1511 cm(-1) band in the T - R difference spectra of hemoglobin is due to the overtone of the Trp W18 fundamental at 756 cm(-1). Measured isotope shifts for 2-H and 15-N substitution at the indole NH group are twice as large for the 1511 cm(-1) band as for W18, and the 1511 cm(-1) intensity scales with that of W18 in the difference spectrum. Moreover, the UVRR excitation profile of the 1511 cm(-1) band tracks that of another tryptophan band, W16. Both are redshifted in hemoglobin, relative to aqueous tryptophan, reflecting H bonding within a hydrophobic environment in the protein. The 2xW18 assignment had been thrown into question by the observation of remnant 1511 cm(-1) intensity in the T - R spectra of hemoglobin labeled with tryptophan-d(5), a substitution that shifts W18 over 50 cm(-1). However, reexamination of the data suggests that this remnant intensity may result from a subtraction artifact arising from the downshift of another difference band, W3, from 1549 cm(-1) in unlabeled protein to 1522 cm(-1) in labeled protein. Restoration of the 2xW18 assignment establishes that the 1511 cm(-1) difference band, which is a useful indicator of the extent of T-state formation in hemoglobin, arises from the same residue, Trpbeta37, that gives rise to essentially all of the T - R signal from tryptophan.     

基于光镊与拉曼光谱的红菇担孢子分析

拉曼光谱作为分子振动光谱,具有无损、无需试剂染色和快速方便的特点,在生物学领域的应用越来越广泛。拉曼镊子是光镊与拉曼光谱的结合,应用拉曼镊子技术收集单个红菇担孢子的拉曼光谱,分析单个担孢子的主要成分,不同的储存方法对担孢子成分的影响等。结果发现,单个担孢子的拉曼光谱反映了担孢子内含物的基本组成,红菇担孢子的孢内主要成分是脂类物质;不同种类的红菇担孢子的拉曼光谱基本相同,经过多年保存的孢子仍然保持其孢子内的主要成分不变。各随机选择10个担孢子的拉曼光谱进行主成分(PCA)判别分析,结果显示红菇属内不同种类的孢子无法区分。结果表明单孢子拉曼光谱可以应用于分析孢子内成分的变化,但应用于真菌分类的可能性有待进一步探索。     

激光喇曼光谱技术在食品科学中的应用

激光喇曼光谱技术是一种非侵入、非弹性的光散射技术,它能够无损地提供丰富的分子结构和物质成分的信息。近来它在食品工业领域表现出很大的应用潜力。本文综述了激光喇曼光谱技术在食品科学中的应用及其新进展。主要包括果蔬农药残留的检测、肉类产品质量检测、伪劣食品鉴定、食物蛋白的研究以及食品加工监控等方面的应用。并对喇曼光谱技术在这些方面的应用前景作了进一步的展望。     

高原鼢鼠和高原鼠兔红细胞低氧适应特征

为探讨高原鼢鼠对低氧高二氧化碳洞道生境及高原鼠兔对高海拔低氧生境的适应机制,用Sysmex SF-3000血细胞分析仪及聚丙烯酰胺凝胶电泳对两种高原动物的血常规及血红蛋白类型进行分析,后者采用聚丙烯酰胺凝胶电泳法。结果表明,高原鼢鼠和高原鼠兔的红细胞数(RBC)、红细胞压积(HCT)及平均红细胞容积(MCV)组间无显著差异(P>0.05),但高原鼢鼠和高原鼠兔的红细胞数显著高于SD大鼠,红细胞压积及平均红细胞容积均显著低于SD大鼠(P<0.05);高原鼢鼠的血红蛋白浓度(HBC)与SD大鼠无显著差异(P>0.05),但显著高于高原鼠兔的HBC(P<0.05)。高原鼢鼠血红蛋白主要有2种类型,高原鼠兔血红蛋白主要有3种类型,而SD大鼠血红蛋白主要有5种类型。从血红蛋白电泳迁移来看,2种高原动物血红蛋白类型有明显的趋同特征并与SD大鼠具有明显的差异。上述结果提示,长期适应高海拔低氧环境的高原动物的红细胞和血红蛋白表现出趋同进化,同时因生境和习性的差异又表现出各自的特异性。