Raman microspectroscopic study of biomolecular structure inside living adhesive cells

Cells adhesion is very important for many physiological processes. Using advanced Raman microspectroscopic technique, we selected T Leukemia cells (Jurkat) as the materials and obtained simultaneously conformation information of various biomolecules inside the whole living cells. By comparing the Raman microspectroscopic spectra of single and adhesive cancer cells, we found for the first time that when cells adhered, the conformation of the biomolecules (DNA, protein, carbohydrates and lipids) inside the cells had different changes: (i) the backbone of double-stranded DNA maintained orderly B-form or modified B-form conformation, whereas the groups of its deoxyribose and bases were modified; (ii) the conformational changes of the main chain and the side chain in the protein were obviously variant. The lines intensity belonging to a-helix and p-sheet decreased, while that of p-turn increased. Tyrosine and tryptophane residues of the protein changed from "buried state" to "exposed state"; the lines intensi     

产前B 超诊断胎儿完全性大动脉转位的超声特征观察

目的:探讨产前B超对胎儿完全性大动脉转位的临床诊断价值。方法:回顾性分析2012年2月至2015年11月我院收治的4例胎儿完全性大动脉转位的B超特征,并对比病理结果。结果:4例完全性大动脉转位胎儿中,1例室间隔缺损,3例四腔心切面正常。左右两室流出道切面情况:4例胎儿大动脉与心室连接关系存在异常,2例胎儿室间隔膜部存在缺损症状。三血管气管切面情况:4例胎儿均仅可见2条血管。结论:对左右两心室流出道切面及三血管气管切面进行观察可得,胎儿完全性大动脉转位具有较为明显的B超特征,产前对胎儿完全性大动脉转位进行B超诊断具有较好的临床价值,建议在医疗单位推广应用。     

黏附细胞中生物大分子结构变化的显微Raman光谱

鉴于细胞黏附作用的重要生物学意义, 选择了T淋巴细胞(Jurkat)为实验对象, 用先进的显微Raman光谱技术, 同时获得用其他方法难以得到的活细胞内数种生物大分子的构象信息. 通过比较单个和黏附细胞的显微Raman光谱的差异发现, 当细胞黏附时, 细胞内生物分子(DNA, 蛋白质, 碳水化合物, 脂类)的构象有不同的变化: (ⅰ) 双链DNA的骨架保持有序的B型或修改的B型构象, 然而它的脱氧核糖和碱基(A, G, C, T)的一些基团被修饰. (ⅱ) 蛋白质构象的主、侧链变化明显不同, 属于a螺旋和b折叠的一些谱线强度下降而b回折的一些谱线强度却明显增加; 酪氨酸和色氨酸从“埋藏状态”变成“暴露状态”; 它的巯基基团的谱线强度也有增加; 二硫键的构象从两种变成3种, 表明细胞黏附引起该蛋白质主链的氢键体系和侧链环境的变化. (ⅲ) 碳水化合物的一些基团同时被修饰. (ⅳ) 膜脂双层的构象变化很明显, 随着黏附细胞数目的增加, 链间侧向相互作用序参数逐渐减少, 提示细胞黏附导致细胞膜的流动性和离子通透性增加.     

竹红菌乙素敏化的人红细胞膜结构光损伤的Raman光谱特征

采用Raman光谱从分子水平揭示了竹红菌乙素光敏损伤的人红细胞膜发生膜蛋白交联和膜脂脂质过氧化导致其功能变化 ;膜流动性和离子通透性增加的本质是竹红菌乙素产生的活性氧 ( ¹O₂ ,O₂ ^-·和·OH等 )破坏了红细胞膜的有序结构 ,使膜蛋白主链结构的α 螺旋、β 折叠明显减少 ,无规卷曲增加并使其侧链结构的巯基基团、吲哚环、对羟苯基环、单基取代苯基环等也明显减少 .与此同时 ,随着光照时间的增加 ,膜脂的反式构象呈先增加后减少的趋势 ,它的扭曲构象则正好相反 .膜蛋白和膜脂构象不灵敏的CH₂ 和CH₃弯曲振动谱线的明显下降 ,揭示它们有链的断裂 .     

Raman spectroscopic study of space structure of membrane proteins and membrane lipids in photodamaged human erythrocyte sensitized by hypocrellin B

Ｈｙｐｏｃｒｅｌｌｉｎａｎｄｉｔｓｄｅｒｉｖａｔｉｖｅｓａｒｅｗｅｌｌｋｎｏｗｎｐｈｏｔｏｓｅｎｓｉｔｉｚｅｒｓ[1,2].ＡｍｏｎｇｔｈｅｍｂｏｔｈｈｙｐｏｃｒｅｌｌｉｎＡ(ＨＡ)ａｎｄｈｙｐｏｃｒｅｌｌｉｎＢ(ＨＢ)ｓｈｏｗｐｒｏｍｉｓｉｎｇａｎｔｉｃａｎｃｅｒａｎｄａｎｔｉｖｉｒａｌａｂｉｌｉｔｙ[1—3].Ｉｎｏｒｄｅｒｔｏｉｎｖｅｓｔｉｇａｔｅｉｔｓｍｅｃｈａｎｉｓｍｓ,ｍａｎｙｍｅｔｈｏｄｓｈａｖｅｂｅｅｎｕｓｅｄｔｏｄｅｔｅｃｔｔｈｅａｃｔｉｖｅｏｘｙｇｅｎｓｕｃｈａｓ1Ｏ2,Ｏ2.-,.ＯＨａｎｄｓｅｍ…     

Pheophorbide a在脂质体介质中的光敏反应特性

Pheophorbidea(PPa)———叶绿素a的一种分解产物 ,是一种光敏剂 .用自旋捕捉和消自旋等ESR技术及激光光解技术研究了PPa在PBS和DPPC脂质体介质中光敏反应的Ⅰ型和Ⅱ型机制 .通过比较发现 ,DPPC脂质体的加入显著增强了PPa光敏反应产生PPa ^- (Ⅰ型 )和¹O₂ (Ⅱ型 )的能力 .这种增强反应源于脂质体对PBS中的PPa聚集态的解聚作用和它对PPa三重激发态的保护作用 .这表明 ,PPa在非均相脂质体体系中的光敏反应有别于均相水体系 ,而表现出更高的光敏效率 .此结果对解释属于非均相生物体系的肿瘤的光动力治疗机理有重要意义 .     

Raman microspectroscopic study of biomolecular structure inside living adhesive cells

Cells adhesion is very important for many physiological processes. Using advanced Raman microspectroscopic technique, we selected T Leukemia cells (Jurkat) as the materials and obtained simultaneously conformation information of various biomolecules inside the whole living cells. By comparing the Raman microspectroscopic spectra of single and adhesive cancer cells, we found for the first time that when cells adhered, the conformation of the biomolecules (DNA, protein, carbohydrates and lipids) inside the cells had different changes: (i) the backbone of double-stranded DNA maintained orderly B-form or modified B-form conformation, whereas the groups of its deoxyribose and bases were modified; (ii) the conformational changes of the main chain and the side chain in the protein were obviously variant. The lines intensity belonging to α-helix and β-sheet decreased, while that of β-turn increased. Tyrosine and tryptophane residues of the protein changed from “buried state” to “exposed state”; the lines intensity of its sulfhydryl group also increased; the conformation of its disulfide bond changed from two kinds to three kinds. These facts suggest that the cells adhesion causes changes in H-bonds organization of the main chain and environment of the side chain in the protein; (iii) the groups of the carbohydrates were also modified simultaneously; (iv) the conformation of the lipids bilayers of the membranes changed obviously; the order parameter for lateral interaction between chains decreased gradually with the increase of number of the adhesive cells. So cells adhesion resulted in an increase in fluidity of the membrane and ion permeability on the membrane.     

Characteristics of photosensitization of Pheophorbide a in liposomal media

Pheophorbide a (PPa), a decomposition product of chlorophyll a, is a photosensitizer. The photosensitization mechanisms (Type Ⅰ and Type Ⅱ) of PPa in simple buffer solutions and in buffer solutions containing double-layered DPPC liposomes have been studied using techniques of ESR, spin-trapping, spin-counteraction and laser flash photolysis. The results showed that adding DPPC liposomes to the buffer solution caused an increase of efficiency of generating ~1O_2 and PPa~- by photoactivating PPa. The increase could be ascribed to the disaggregation of hydrophobic PPa caused by the addition of liposomes and the protective effect of liposomal media on the triplet state of PPa. It is concluded that the photosensitization of PPa in liposomal systems is different from that in simple aqueous solutions, and shows higher efficacy. The results will be useful to elucidating the mechanisms of photodynamic therapy of cancer.