Thermally induced gelation of paramyosin from scallop adductor muscle

ABSTRACT:   Thermally induced gelation of paramyosin from scallop smooth adductor muscle was investigated by dynamic rheological measurements under various conditions. The paramyosin thermal gel was produced at pH 6.5 and 7.2 at temperatures above 30°C through a two-step increase in storage (G') and loss (G') moduli; these values were higher than in gels produced from actomyosin at a high temperature. The thermal gel properties were very firm and brittle. In contrast, one main peak of G' was observed during gelation at pH 8.0. The gel produced at pH 8.0 was more transparent and less soluble in a 6 M urea−0.5 M NaCl solution than those formed either at pH 6.5 or 7.2. These differences in the thermal gel properties are presumed to derive from the pH dependence of the gel matrix-forming process, such as oxidative cross-linking between cysteine residues, rather than from the thermal unfolding of the paramyosin molecules. The thermal gelation profile of chymotrypsin-digested paramyosin showed marked depression of G' at high temperature.     

犬疥（璊）副肌球蛋白抗血清的制备及临床应用

目的：利用现代分子生物学方法,建立一种准确率更高的犬疥（璊）病的诊断方法,为犬疥（璊）病的治疗提供诊断基础.方法：收集犬疥（璊）,抽提总RNA并将其反转录为cDNA;以该cDNA为模板,参考其它哺乳动物副肌球蛋白的基因序列特征,设计引物扩增含有多个抗原表位的犬副肌球蛋白的部分cDNA序列;构建原核表达载体,表达及纯化目的蛋白片段;以纯化的目的蛋白片段为抗原,免疫BALB/c小鼠制备抗血清;以制备的抗血清为一抗,通过间接ELISA法测定患病犬痂皮组织中疥（璊）副肌球蛋白片段的存在,进而判断是否有疥（璊）感染.结果：成功构建了副肌球蛋白的原核表达载体,命名为pET28a-Para-202;通过诱导、纯化获得了重组蛋白;该重组蛋白抗原免疫小鼠后获得高效价的抗血清;以该抗血清为工具,通过间接ELISA法极大提高了犬疥（璊）感染的诊断率,为该病治疗提供了重要的参考依据.     

皱纹盘鲍副肌球蛋白的分离纯化及初步性质研究

为了研究鲍鱼肌原纤维中副肌球蛋白(PM)的性质,以皱纹盘鲍为原料,采用硫酸铵盐析和羟基磷灰石柱层析相结合的方法,从肌肉中纯化得到PM。利用肽质量指纹图谱测定其内部肽片段氨基酸序列;采用双向电泳测定其等电点;用圆二色谱研究其二级结构特征,进一步利用红外光谱对其官能团进行表征。SDS-PAGE结果显示,PM分子量约为97.0 ku。肽质量指纹图谱分析获得36条肽段共403个氨基酸残基,与盘鲍和太平洋牡蛎PM的一致性分别为99.7%和72.0%,表明纯化蛋白确为PM。双向电泳测得PM等电点约为5.4,证明其为一种酸性蛋白。圆二色谱结果显示,PM溶液在192 nm处有一正吸收峰,在208和223 nm处各有一负吸收峰,具有典型α-螺旋结构的特征谱峰型;其热变性温度为58.1°C。红外光谱分析结果进一步证实,PM具有完整的α螺旋结构。对鲍鱼PM理化特性进行研究,可为鲍鱼质构相关研究及鲍鱼制品深加工提供一定的理论基础。