采用动态高压微射流(Dynamic high pressure microfluidization,DHPM)技术对生物解离大豆膳食纤维进行改性,探讨其对膳食纤维组成、理化及功能特性的影响。结果表明:生物解离和动态高压微射流技术均可有效提高大豆膳食纤维中可溶性膳食...采用动态高压微射流(Dynamic high pressure microfluidization,DHPM)技术对生物解离大豆膳食纤维进行改性,探讨其对膳食纤维组成、理化及功能特性的影响。结果表明:生物解离和动态高压微射流技术均可有效提高大豆膳食纤维中可溶性膳食纤维的含量,降低不可溶性膳食纤维的含量,使不可溶性膳食纤维与可溶性膳食纤维质量分数的比值达到1.87;通过对比不同处理压力的生物解离大豆膳食纤维中其余成分的含量可知,DHPM对生物解离膳食纤维中含水率影响不显著(P>0.05)。生物解离和动态高压微射流技术能明显改善膳食纤维的水化性质和持油力,但对阳离子交换能力的影响不显著;在pH值7条件下,不同压力处理膳食纤维的重金属离子吸附能力差异不显著,且膳食纤维在pH值7条件下对同种重金属离子的吸附效果优于pH值为2的情况。膳食纤维对葡萄糖吸收能力随处理压力的提高而依次增大,达到200 MPa时略有下降,且不同压力处理膳食纤维的葡萄糖吸收能力均随葡萄糖浓度的增加而提高;200 MPa处理压力下的生物解离膳食纤维的α-淀粉酶抑制能力最高,为18.42%,较0~150 MPa处理的膳食纤维样品分别提高了约36%、32%、28%和27%。随动态高压微射流技术处理压力的增加,膳食纤维结合胆汁酸的能力有所升高。因此,动态高压微射流技术可以作为提高膳食纤维生理功能的有效途径。展开更多
目的:探究超声预处理对大豆分离蛋白(soybean protein isolate,SPI)-儿茶素非共价/共价复合物结构及功能的影响。方法:对SPI进行超声处理后,在不同pH值(3.0、7.0、9.0、12.0)下与儿茶素通过非共价/共价结合方式制备复合物,并通过十二烷...目的:探究超声预处理对大豆分离蛋白(soybean protein isolate,SPI)-儿茶素非共价/共价复合物结构及功能的影响。方法:对SPI进行超声处理后,在不同pH值(3.0、7.0、9.0、12.0)下与儿茶素通过非共价/共价结合方式制备复合物,并通过十二烷基硫酸钠-聚丙烯酰胺凝胶电泳(sodium dodecyl sulfate-polyacrylamide gel electrophoresis,SDS-PAGE)来验证复合物的形成以及蛋白与多酚结合程度,采用荧光光谱法、傅里叶变换红外光谱法及分子对接技术研究SPI与儿茶素之间的相互作用以及SPI结构的变化,通过起泡性、泡沫稳定性、溶解度、浊度及抗氧化能力等指标考察复合物功能性质的变化。结果:SDS-PAGE证实了非共价/共价复合物的形成以及超声预处理对复合物结合程度具有影响,SPI超声后在pH 12时结合的儿茶素最多;荧光光谱和傅里叶变换红外光谱分析结果表明非共价/共价复合物中SPI的二级结构发生改变,与未处理的SPI样品相比,α-螺旋和β-折叠相对含量下降,β-转角和无规卷曲相对含量增加,色氨酸和酪氨酸基团暴露增多,其中pH 12条件下超声预处理效果最显著,β-转角相对含量增加至40.20%,无规卷曲相对含量增加至28.61%,SPI结构变得更加舒展及松散;经超声预处理后,SPI及复合物的溶解度、浊度、起泡性、泡沫稳定性及抗氧化能力均有所增加,其中抗氧化能力提升最显著,在pH 12条件下共价复合物对1,1-二苯基-2-三硝基苯肼自由基清除率提高至未处理SPI样品的5.5倍,对2,2’-联氮-双(3-乙基苯并噻唑啉-6-磺酸)阳离子自由基清除率提高至未处理SPI样品的4.8倍;分子对接结果也验证了SPI与儿茶素非共价结合的作用力主要是氢键和疏水作用。结论:SPI经过超声预处理后在pH 12的条件下与儿茶素结合最强,其共价复合物最稳定,起泡性与抗氧化性得到显著提升。展开更多
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
Seed germination is associated with grain yield and quality in crop production.Gibberellic acid(GA)serves as a major phytohormone in the promotion of seed germination.It is synthesized in the embryos and transmitted t...Seed germination is associated with grain yield and quality in crop production.Gibberellic acid(GA)serves as a major phytohormone in the promotion of seed germination.It is synthesized in the embryos and transmitted to the aleurone layers,where GA triggers the synthesis and secretion of a set of hydrolases,especiallyα-amylase.Subsequently,the storage nutrients such as starch in the endosperm are digested by these hydrolases and absorbed by the embryo to sustain seed germination and early seedling establishment(Kaneko et al,2002).The detailed GA biosynthesis process has been well studied and thoroughly reviewed in several literatures(Sakamoto et al,2004;Reinecke et al,2013).Briefly,geranylgeranyl diphosphate(GGDP)is turned into ent-kaurene by two terpene synthases,ent-copalyl diphosphate synthase(CPS)and ent-kaurene synthase(KS).Subsequently,the conversion of GA precursor ent-kaurene to ent-kaurenoic acid is catalyzed by ent-kaurene oxidase(KO),and that from ent-kaurenoic acid to GA12 is catalyzed by ent-kaurenoic acid oxidase(KAO).Ultimately,GA12 is converted to various GA intermediates and bioactive GAs by GA20-oxidase(GA20ox)and GA3-oxidase(GA3ox),respectively.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.
基金the National Natural Science Foundation of China(Grant No.31701395)the special research funds for the Central Public Research Institute of the China National Rice Research Institute(Grant No.2017RG002-5)the special research funds of State Key Laboratory of Rice Biology(Grant No.2017ZZKT10105).
文摘Seed germination is associated with grain yield and quality in crop production.Gibberellic acid(GA)serves as a major phytohormone in the promotion of seed germination.It is synthesized in the embryos and transmitted to the aleurone layers,where GA triggers the synthesis and secretion of a set of hydrolases,especiallyα-amylase.Subsequently,the storage nutrients such as starch in the endosperm are digested by these hydrolases and absorbed by the embryo to sustain seed germination and early seedling establishment(Kaneko et al,2002).The detailed GA biosynthesis process has been well studied and thoroughly reviewed in several literatures(Sakamoto et al,2004;Reinecke et al,2013).Briefly,geranylgeranyl diphosphate(GGDP)is turned into ent-kaurene by two terpene synthases,ent-copalyl diphosphate synthase(CPS)and ent-kaurene synthase(KS).Subsequently,the conversion of GA precursor ent-kaurene to ent-kaurenoic acid is catalyzed by ent-kaurene oxidase(KO),and that from ent-kaurenoic acid to GA12 is catalyzed by ent-kaurenoic acid oxidase(KAO).Ultimately,GA12 is converted to various GA intermediates and bioactive GAs by GA20-oxidase(GA20ox)and GA3-oxidase(GA3ox),respectively.
