MALDI-TOF MS和电子光谱技术研究海兔肝铁蛋白亚基电离和释放铁动力学特性

选用肽质量指纹谱(peptide mass fingerprint,PMF)技术鉴定质谱纯海兔肝铁蛋白(liver ferritin ofAplysia,ALF)。来源于基质辅助激光解吸电离飞行时间质谱(MALDI-TOF MS)仪中的激光和基质芥子酸协同解吸海兔肝铁蛋白(ALF)为带双电荷、单电荷[M H] 和二聚体的亚基离子,并可供质谱分析。ALF亚基的质荷比m/z分别为9784.03[M 2H]2 、19678.42[M H] 和39387.80[2M H] ,其中亚基分子量[M H] 略小于鲨鱼肝铁蛋白(liver ferritin of shark,SLF)。在弱碱介质(pH8.0)条件下,电子光谱技术研究指出,抗坏血酸以1/2级反应方式参与ALF释放铁全过程,同时又使ALF以一级反应动力学方式释放铁,呈现两种不同的速率。推测这一异常现象可能与ALF含低铁量、亚基调节能力和海兔的进化地位有关。     

MALDI-TOF质谱、电泳和透射电子显微镜技术研究魟鱼肝铁蛋白H和L亚基特性

小批量制备质谱纯魟鱼肝铁蛋白(liver ferritin of Dasyatis akajei, DALF),以透射电子显微镜术(TEM)测定DALF、蛋白壳和铁核的分子尺寸.SDS-PAGE技术指出,DALF由H 和L两种不同类型的亚基组成.采用肽质量指纹图谱(PMF)技术进一步佐证H和L亚基类型和同源性.氧化还原剂中性红、劳氏紫、甲基紫精和 pH 1.5酸度均无法削弱DALF的H-L和L-L亚基之间的相互作用强度、并解吸出L亚基离子,供MALDI-TOF质谱仪分析.通过增加激光强度和降低基质pH途径,可直接分析DALF的H和L亚基的分子量,指出DALF中H-L和L-L亚基之间的相互作用强度明显高于H-H亚基类型.     

电泳/质谱技术研究鲨鱼肝铁蛋白及亚基多聚体特性

改良鲨鱼肝铁蛋白(liver ferritin ofsphyrna zygaena,SZLF)分离技术,并结合非变性梯度聚丙烯酰胺凝胶电泳(NGPAGE)制备质谱纯SZLF,以维系铁蛋白分子和它的亚基之间的作用类型,供研究铁蛋白结构与功能。实验结果表明,SZLF由分子量约为20kDa的单类型亚基组成。SZLF和它的亚基均组成不同的聚合体。聚合体类型和聚合数目与铁蛋白亚基和分离介质有关。MALDI-TO F质谱仪的激光和基质协同能有效解吸SZLF中的亚基成为准分子离子,并供质量分析,其亚基特征质谱峰m/z值分别为10889.35和22030.45,确定为带双电荷[M 2H]2 和单电荷[M H] 的SZLF亚基分子量。SDS-PAGE和变性IEF技术研究指出,形成不同聚合态的SZLF,其分子之间的相互作用强度高于SZLF亚基自身,难以通过MALDI-TOF质谱技术测定其亚基的结构信息。尽管SZLF由单类型亚基组成,但它能通过聚合体和自身亚基之间的相互作用差异性发挥极其重要的生理功能。     

电泳和质谱技术研究4种胰脏铁蛋白的亚基类型和等电点特性

采用电泳和质谱技术对所制备的鸡、鸭、牛和猪胰脏铁蛋白的亚基类型和等电点特性进行了研究。采用天然聚丙烯酰胺凝胶电泳(PAGE)技术研究的结果表明,上述4种铁蛋白呈现不同的迁移率,据此可知鸡胰铁蛋白的相对分子质量(Mr)>鸭胰铁蛋白的Mr>黄牛胰铁蛋白的Mr>猪胰铁蛋白的Mr,而且均大于马脾铁蛋白(HSF)的Mr。采用十二烷基硫酸钠(SDS)-PAGE技术研究的结果表明,上述4种铁蛋白均由H(heavy chain)和L(light chain)类型的亚基组成,但H和L亚基的相对数量（即H/L亚基数量的比值）有差别。采用肽指纹图谱技术分别鉴定各铁蛋白的H和L亚基。选用变性等电聚焦方法研究发现,上述4种铁蛋白分别由3～6种不同等电点的亚基聚合体组成,说明铁蛋白的H和L亚基之间呈现复杂的相互作用和不同的聚合体。不同陆生动物胰脏铁蛋白亚基之间相互作用的强度和聚合态存在着差异,这一差异特性可能与调控铁蛋白释放铁的速率有关,也与动物对铁的需求和铁解毒速率有关。     

鲨鱼肝铁蛋白亚基解离与组装机理的研究

小批量制备质谱纯鲨鱼肝铁蛋白(Liver Ferritin of Sphyrna zygaena,SZLF)。在弱酸介质(pH1.0)中,天然电泳结果显示,SZLF蛋白质亚基20 min后开始解离。选用透射电子显微镜跟踪SZLF亚基解离与重组装全过程和蛋白壳与铁核尺寸变化,发现SZLF在亚基酸解离过程中,随着pH值的降低,铁核和蛋白壳的尺寸呈现相同的变化趋势,这种变化趋势可能与铁核内层铁的释放和蛋白壳的解离与去折叠有关。SZLF蛋白壳的重组装过程则是一个快速过程,并且是由松散熔球态向紧密态转变的过程。SZLF由单类型亚基组成,而马脾铁蛋白(Horse Spleen Ferritin,HSF)由H和L两种亚基类型组成。在基质pH3.0条件和激光辅助下,混合HSF和SZLF仍然可释放各自的亚基且形成准亚基离子,供基质辅助激光解析电离飞行时间质谱分析,说明此时SZLF的亚基间相互作用强度减弱但并没有去折叠。TEM技术在铁蛋白解离和重组装过程中的应用,为进一步研究铁蛋白纳米包装的过程和机理提供新颖的、可行的和更加直观的研究手段。     

用圆二色性和荧光光谱技术研究纳米吡啰红G核-铁蛋白的构建机理

小批量制备了电泳纯鲨鱼肝铁蛋白(Liver ferritin ofSphyrna zygaena,SZLF),对SZLF的结构与功能进行了研究.在pH=2.0~10.0条件下,选用圆二色性(Circular dichroism,CD)光谱技术研究了SZLF和脱铁核SZLF(apoSZLF)二级结构转换的基本特征和变化趋势,揭示了SZLF蛋白壳的亚基稳定性、相互作用强度和去折叠现象.利用酸碱中和方法,解离SZLF蛋白壳亚基,并再次构建成完整SZLF.用紫外-可见分光光度法和荧光光度法研究了构建纳米吡啰红G核-铁蛋白的途径.定量分析结果表明,每分子apoSZLF可捕获12分子吡啰红G于蛋白壳内,构建纳米吡啰红G核-铁蛋白.分析了apoSZLF直接捕获和释放吡啰红G的途径与速率,为后续构建高存量纳米顺铂核-铁蛋白药物载体提供了可行性技术.     

用MALDI-TOF质谱和电子光谱研究纳米胰岛素核-铁蛋白的构建技术和特性

小批量制备了电泳纯鲨鱼肝铁蛋白(Liver ferritin of Sphyma zygaena, SZLF). 用透射电子显微镜技术研究SZLF的铁核和蛋白壳亚基解离和重组过程. 用盐酸解离(pH=1.5)和分离膜透析技术制备铁蛋白亚基, 并用酸碱中和方法重组亚基成为脱铁核铁蛋白(apoSZLF), 同时将胰岛素(Insulin, INS)包裹于apoSZLF蛋白壳内, 构建纳米INS核-SZLF. 用电子光谱、MALDI-TOF质谱和SDS-PAGE技术分别揭示了纳米INS核-SZLF分子结构的真实性, 提出铁蛋白亚基包裹INS构建为纳米INS核-铁蛋白的途径.     

蛋白质辅助基质提高激光解吸/电离多肽离子化率和绝对强度的研究

人血清转铁蛋白(Human serum transferrin, HTF)、牛血清白蛋白(Bovine serum albumin, BSA)、鲨鱼肝铁蛋白(Sphyrna zygaena liver ferritin, SZLF)、马脾铁蛋白(Horse spleen ferritin, HSF)均能辅助基质提高激光解吸/电离胰岛素(Insulin, INS)和海兔酸性多肽(Aplysia acidic peptide, AP)离子化率和质谱峰的绝对强度(简称为绝对强度), 其中绝对强度分别提高10和4倍, 这一现象不依赖于INS浓度, 而与蛋白质类型和结构有关. SZLF和脱铁核SZLF(apoSZLF)辅助基质提高INS绝对强度的能力几乎相同, 蛋白质中的金属离子含量对这种效应无明显影响, 主要取决于蛋白质的氨基酸组成与结构. 采用胶内酶解和肽指纹技术(PMF)鉴定HTF过程中, 发现基质中分别添加SZLF, apoSZLF和HSF后, HTF肽片段质谱检测的质谱峰数目及绝对强度均有明显增加, 进一步提高了数据库鉴定HTF的可信度.     

铁蛋白纳米蛋白壳结构与功能研究新进展

铁蛋白是广泛存在于生物体内的储存铁的蛋白质,它参与生物体内的铁代谢.本文从铁蛋白的亚基结构、血红素-电子隧道、铁氧化酶位点和捕获重金属离子角度,综述铁蛋白纳米蛋白壳的结构与功能研究的新进展.     

MALDI-TOF质谱和电子光谱技术研究人血清铁蛋白释放铁的动力学

采用MALDI-TOF质谱技术研究血清混合蛋白质的组成,用电子光谱技术分析人血清铁蛋白(Serumferritin,SF)释放铁的动力学过程和规律.结果表明,在人血清中,以Na₂S₂O₄为电子供体时,SF释放铁的速率极快,无法采用常规分光光度法进行检测;以抗坏血酸为电子供体时,SF以一级反应动力学方式释放铁,认为人血清中其它蛋白质协助或参与调控铁蛋白进行快速释放铁反应,从而满足人体对铁的需求.     

Dichroism of absorption and polarization of phosphorescence of molecules of the closed form of nitrobenzospirothiopyran

The spectral-polarization characteristics of absorption and phosphorescence of molecules of the initial form of nitro-substituted indolinospirobenzothiopyran were studied in oriented polyethylene films and in solutions with different polarity. An oscillator model of the electron transitions responsible for the formation of absorption and luminescence spectra was suggested. It was established that the principal differences in the spectral and photophysical properties of the compound studied and its oxygen-containing analog are associated with the fact that the electronegativity of the S atom is lower than that of the O atom. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1143–1146, June, 1997.     

非那雄胺合成工艺改进

非那雄胺能抑制5α-还原酶的活性,明显降低二氢睾酮水平,是一种治疗良性前列腺增生的有效药品。该合成工艺以甾烯酮酸为原料,将其与氯化亚砜反应,无须分离即与叔丁胺反应得17β-酰胺化合物,再氧化开环,环合,氢化,脱氢合成了非那雄胺。经元素分析、IR、1HNMR、13CNMR、MS分析表征了其结构。该法无须使用昂贵的2,2-二吡啶二硫化物和剧毒药品苯亚硒酸酐,且以乙酸铵代替氨气,降低了对设备的要求和腐蚀,更适用于工业生产。     

Determination of heats of detonation and influence of components of composite explosives on heats of detonation of high explosives

The heats of detonation of 20 simple high explosives and explosive mixtures were determined by means of an adiabatic detonation calorimeter designed by the authors. The results indicated that the performance of the instrument was reliable and the experimental data were very accurate. For explosive mixtures, there was a linear accumulative relationship between the heats of detonation of the explosive mixture and its components. Accordingly, the heats of detonation of explosive mixtures could be calculated directly from the heats of detonation of simple explosives and the characteristic heats of other components. The experiments showed that the gold or brass shell of the cylindrical charge could be substituted by a thick-walled porcelain shell, which had the advantage of cheapness.

     

Synthesis of phenolic components of Grains of Paradise

Two vanilloids, (5E)-8-(4-hydroxy-3-methoxyphenyl)oct-5-en-4-one (1) and 4-[3-hydroxydecyl]-2-methoxyphenol (2), isolated from the dried seeds of Grains of Paradise (Aframomum melegueta), were synthesized; the latter compound was made as the S-enantiomer and the material derived from the seeds was found to be a 1:1.7 mixture of the R and S isomers. The synthetic route used should allow the preparation of analogs having extended alkyl chains and consequently different lipophilicity, and 3, a homolog of 2, was also prepared.     

Summary of development of the theory of stability of colloids and thin films

In this review, the research of the author in the field of colloidal systems is summarized. The factors influencing colloidal stability are systematized and analyzed. Examples are presented to illustrate the practical utilization of the theory of stability of colloids and thin films.This review was prepared on the basis of the works of the author, which were awarded the State Premium for 1991 in the field of science and technology, chemistry section.Institute of Physical Chemistry, Russian Academy of Sciences, 117915 Moscow. Translated from Izvestiya Akademii Nauk, Seriya Khimicheskaya, No. 8, pp. 1708–1717, August, 1992.     

Study of hydration of two cements of different strengths

Main hydration products of two cement pastes, i.e. CSH-gel, portlandite (P) (and specific surface S) were studied by static heating, and by SEM, TEM and XRD, as a function of cement strength (C-33 and C-43) hydration time (th) and subsequent hydration in water vapour.Total change in mass on hydration and air drying, M_o, increased with strength of cement paste and with hydration time. Content of water escaping at 110 to 220°C, defined as water bound with low energy, mainly interlayer and hydrate water, was independent on cement strength but its content increased with (th). Content of chemically bound (zeolitic) water in CSH-gel, escaping at 220-400°C, was slightly dependent on strength and increased with (th). It was possibly derived from the dehydroxylation of CSH-gel and AFm phase. Portlandite water, escaping at 400-500°C, was independent on cement strength and was higher on longer hydration. Large P crystals were formed in the weaker cement paste C-33. Smaller crystals were formed in C-43 but they increased with (th). Carbonate formated on contact with air (calcite, vaterite and aragonite), decomposed in cement at 600-700^oC. It was high in pastes C-33(1 month) and C-43(1 month), i.e. 5.7 and 3.3%, respectively; it was less than 1% after 6 hydration months (low sensitivity to carbonation) in agreement with the XRD study showing carbonates in the air dry paste (1month), and its absence on prolonged hydration (6 months) and on acetone treatment. Water vapour treatment of (6 months) pastes or wetting-drying increased this sensitivity.Nanosized P-crystals, detected by TEM, could contribute to the cement strength; carbonate was observed on the rims of gel clusters.This revised version was published online in November 2005 with corrections to the Cover Date.     

氯氧化镁生成热的研究

用氧化镁氯化镁水溶液制备了8水合氯氧化镁[nMg(OH)2·MgCl2·8H2O], 并测定了其在盐酸中的溶解热, 实验结果表明, 氯氧化镁溶解热与n值呈线性关系, 根据溶解热求出5Mg(OH)2·MgCl2·8H2O和3Mg(OH)2·MgCl2·8H2O的生成热分别为-7727.1和5888.1kJ·mol^1^-。     

Thermodynamics of the formation of oxosulfides of rare-earth elements

The enthalpies of solution of several oxosulfides of rare-earth elements and the high-temperature enthalpies of oxosulfides and oxosulfates of lanthanum and yttrium were measured using solution calorimetry and high-temperature microcalorimetry techniques. Standard enthalpies of formation and some thermodynamic properties of oxosulfides and oxosulfates were calculated. Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2 pp. 294–297, February, 1997.     

恶臭嗅辨实验室建设探讨

针对恶臭测试的环境影响问题,提出了解决的实例方案,并对方案的要点及优缺点进行讨论,此方案在实际操作中具有较好的效果。