Protein phosphorylation,one of the major post-translational modifications,plays a crucial role in cell signaling,DNA replication,gene expression and differentiation;and alters enzyme activity and other biological acti...Protein phosphorylation,one of the major post-translational modifications,plays a crucial role in cell signaling,DNA replication,gene expression and differentiation;and alters enzyme activity and other biological activities;and regulates cell proliferation and enlargement,phytohormone biosynthesis and signaling,plant disease resistance,and grain filling and quality during rice seed development.Research work on protein phosphorylation started in the 1950 s with the discovery of phosphorylase a and phosphorylase b which are phospho and dephospho forms of the same enzyme.Over the last decade,rice proteomics has accomplished tremendous progress in setting up techniques to proteome nearly all tissues,organs and organelles.The progress made in this field is evident in number of research works.However,research on rice protein phosphorylation is still at its infancy and there are still many unanswered questions.In this review,the general description of protein phosphorylation,including history,structure,frequency of occurrence and function,are discussed.This work also elucidates the different methods for identification,qualification and finally,the progress in rice phosphoproteome research and perspectives.展开更多
为探究双酶不同酶解路线制得大米蛋白肽的性质差异,研究采用胰蛋白酶(A)和碱性蛋白酶(B)按不同酶解路线对大米蛋白进行酶解,制备了5种大米蛋白肽(A^(1)B^(1)、A^(1)B^(2)、A^(2)B^(1)、A^(1*)B^(2)、A^(2)B^(1*)),对其水解度、基本成分...为探究双酶不同酶解路线制得大米蛋白肽的性质差异,研究采用胰蛋白酶(A)和碱性蛋白酶(B)按不同酶解路线对大米蛋白进行酶解,制备了5种大米蛋白肽(A^(1)B^(1)、A^(1)B^(2)、A^(2)B^(1)、A^(1*)B^(2)、A^(2)B^(1*)),对其水解度、基本成分、氨基酸组成、微观结构、二级结构、分子量分布、风味和体外抗氧化活性等进行分析。结果表明,A^(2)B^(1)组的蛋白含量最高达到90.69%,肽含量高达72.73%;各路线的水解度大于17.60%,水解较为完全;微观结构均由不规则块状变为球体状,A1B2组和A^(1*)B^(2)组球体壁较厚,A^(2)B^(1)组和A^(2)B^(1*)组球体壁较薄,A^(1)B^(1)组为球体碎片;各路线的必需氨基酸含量比大米蛋白低,A1B2组必需氨基酸含量最高;二级结构以多种构象并存,各路线二级结构均以β-转角为主,占二级结构的44.62%~47.18%;各路线酶解产物多为低分子量的多肽,分子量低于5 k Da的多肽占92.09%~93.71%;A1B2样品鲜味最强,涩味最弱,A^(2)B^(1)样品咸味和苦味最弱;相比于A^(1)B^(1)组、A1B2组和A^(1*)B^(2)组,A^(2)B^(1)组和A^(2)B^(1*)组的抗氧化活性更强。通过对双酶不同酶解路线大米蛋白肽的性质研究,综合基本成分、肽含量、氨基酸组成、风味和抗氧化活性评价,A^(2)B^(1)组的品质最佳。展开更多
该文采用碱法和酶法两步加工碎米,制备得到纯度较高的大米蛋白。通过研究米粉粒度、pH值、温度、水料比和时间对提取率的影响,确定碱法制备大米蛋白的较佳工艺条件为:米粉粒度80目,pH 11.0,温度50℃,水料比8,时间120 m in。采用α-淀粉...该文采用碱法和酶法两步加工碎米,制备得到纯度较高的大米蛋白。通过研究米粉粒度、pH值、温度、水料比和时间对提取率的影响,确定碱法制备大米蛋白的较佳工艺条件为:米粉粒度80目,pH 11.0,温度50℃,水料比8,时间120 m in。采用α-淀粉酶对大米蛋白进行纯化,酶解条件为:加酶量60 U/g,pH 6.0,温度50℃,时间30 m in。在上述工艺条件下制备大米蛋白,提取率为73.22%,纯度为88.75%。展开更多
【目的】建立在中低温度下直接酶解米糠制备短肽的优化工艺。【方法】采用二次回归正交旋转组合设计优化直接酶解米糠制备短肽的工艺条件,其中总糖含量测定采用蒽酮比色法,水解度(degree of hydrolysis,DH)采用pH-stat法,蛋白质回收率...【目的】建立在中低温度下直接酶解米糠制备短肽的优化工艺。【方法】采用二次回归正交旋转组合设计优化直接酶解米糠制备短肽的工艺条件,其中总糖含量测定采用蒽酮比色法,水解度(degree of hydrolysis,DH)采用pH-stat法,蛋白质回收率采用凯氏定氮法。【结果】确定直接酶解米糠制备短肽最佳工艺条件为:米糠先经糖酶(viscozyme)反应2h去除糖类杂质,然后用碱性蛋白酶(alcalase)和胰蛋白酶双酶水解,最适pH8.2,温度45℃,alcalase与胰蛋白酶酶活比59﹕41,总酶活5750U/g底物,水解时间3h。在此条件下,DH为23.04%,蛋白质回收率为84.33%,酸溶性多肽(TCA-SN)为68.40%,短肽分子量主要集中在1000D以下。【结论】在中低温和偏中性(pH8.2)条件下,采用碱性蛋白酶和胰蛋白酶双酶直接酶解米糠制备短肽,与先提取蛋白后酶解制备短肽的方法相比,具有操作步骤简单、蛋白质利用率高等特点,是一种制备米糠肽的新途径。展开更多
文摘Protein phosphorylation,one of the major post-translational modifications,plays a crucial role in cell signaling,DNA replication,gene expression and differentiation;and alters enzyme activity and other biological activities;and regulates cell proliferation and enlargement,phytohormone biosynthesis and signaling,plant disease resistance,and grain filling and quality during rice seed development.Research work on protein phosphorylation started in the 1950 s with the discovery of phosphorylase a and phosphorylase b which are phospho and dephospho forms of the same enzyme.Over the last decade,rice proteomics has accomplished tremendous progress in setting up techniques to proteome nearly all tissues,organs and organelles.The progress made in this field is evident in number of research works.However,research on rice protein phosphorylation is still at its infancy and there are still many unanswered questions.In this review,the general description of protein phosphorylation,including history,structure,frequency of occurrence and function,are discussed.This work also elucidates the different methods for identification,qualification and finally,the progress in rice phosphoproteome research and perspectives.
文摘为探究双酶不同酶解路线制得大米蛋白肽的性质差异,研究采用胰蛋白酶(A)和碱性蛋白酶(B)按不同酶解路线对大米蛋白进行酶解,制备了5种大米蛋白肽(A^(1)B^(1)、A^(1)B^(2)、A^(2)B^(1)、A^(1*)B^(2)、A^(2)B^(1*)),对其水解度、基本成分、氨基酸组成、微观结构、二级结构、分子量分布、风味和体外抗氧化活性等进行分析。结果表明,A^(2)B^(1)组的蛋白含量最高达到90.69%,肽含量高达72.73%;各路线的水解度大于17.60%,水解较为完全;微观结构均由不规则块状变为球体状,A1B2组和A^(1*)B^(2)组球体壁较厚,A^(2)B^(1)组和A^(2)B^(1*)组球体壁较薄,A^(1)B^(1)组为球体碎片;各路线的必需氨基酸含量比大米蛋白低,A1B2组必需氨基酸含量最高;二级结构以多种构象并存,各路线二级结构均以β-转角为主,占二级结构的44.62%~47.18%;各路线酶解产物多为低分子量的多肽,分子量低于5 k Da的多肽占92.09%~93.71%;A1B2样品鲜味最强,涩味最弱,A^(2)B^(1)样品咸味和苦味最弱;相比于A^(1)B^(1)组、A1B2组和A^(1*)B^(2)组,A^(2)B^(1)组和A^(2)B^(1*)组的抗氧化活性更强。通过对双酶不同酶解路线大米蛋白肽的性质研究,综合基本成分、肽含量、氨基酸组成、风味和抗氧化活性评价,A^(2)B^(1)组的品质最佳。
文摘该文采用碱法和酶法两步加工碎米,制备得到纯度较高的大米蛋白。通过研究米粉粒度、pH值、温度、水料比和时间对提取率的影响,确定碱法制备大米蛋白的较佳工艺条件为:米粉粒度80目,pH 11.0,温度50℃,水料比8,时间120 m in。采用α-淀粉酶对大米蛋白进行纯化,酶解条件为:加酶量60 U/g,pH 6.0,温度50℃,时间30 m in。在上述工艺条件下制备大米蛋白,提取率为73.22%,纯度为88.75%。
文摘【目的】建立在中低温度下直接酶解米糠制备短肽的优化工艺。【方法】采用二次回归正交旋转组合设计优化直接酶解米糠制备短肽的工艺条件,其中总糖含量测定采用蒽酮比色法,水解度(degree of hydrolysis,DH)采用pH-stat法,蛋白质回收率采用凯氏定氮法。【结果】确定直接酶解米糠制备短肽最佳工艺条件为:米糠先经糖酶(viscozyme)反应2h去除糖类杂质,然后用碱性蛋白酶(alcalase)和胰蛋白酶双酶水解,最适pH8.2,温度45℃,alcalase与胰蛋白酶酶活比59﹕41,总酶活5750U/g底物,水解时间3h。在此条件下,DH为23.04%,蛋白质回收率为84.33%,酸溶性多肽(TCA-SN)为68.40%,短肽分子量主要集中在1000D以下。【结论】在中低温和偏中性(pH8.2)条件下,采用碱性蛋白酶和胰蛋白酶双酶直接酶解米糠制备短肽,与先提取蛋白后酶解制备短肽的方法相比,具有操作步骤简单、蛋白质利用率高等特点,是一种制备米糠肽的新途径。
