食品科学 ›› 0, Vol. ›› Issue (): 0-0.

• 基础研究 •    下一篇

芋艿分离蛋白的部分性质测定

黄友如1,王教飞1,朱东兴2,李昕蓓1,徐田甜1   

  1. 1. 常熟理工学院
    2. 常熟理工学院生物与食品工程学院
  • 收稿日期:2015-09-22 修回日期:2016-06-13 出版日期:2016-08-15 发布日期:2016-08-30
  • 通讯作者: 黄友如 E-mail:huangyouru@aliyun.com
  • 基金资助:
    “十二五”农村领域国家科技计划课题

Partial Characteristics Determination of Taro Protein Isolates

  • Received:2015-09-22 Revised:2016-06-13 Online:2016-08-15 Published:2016-08-30

摘要: 针对芋艿分离蛋白的等电点、变性温度、氨基酸组成及亚基相对分子质量分布等重要物化性质进行了研究,结果显示,芋艿分离蛋白各组分的等电点主要集中在pI为6.73和5.21两个条带,分别占分离蛋白总量的16.36%和27.30%;SDS-PAGE分析表明芋艿分离蛋白主要由四种亚基组成,其相对分子质量分别分布在57 000、46 300、34 200和8 500左右,添加巯基乙醇可增加相对分子质量在23 100左右的条带,证明芋艿分离蛋白亚基间有二硫键的交联;DSC分析确定芋艿分离蛋白的变性温度为71.3±0.2℃,变性焓ΔH为1.550 J/g;氨基酸组成分析表明,非极性氨基酸含量占37.26%,极性氨基酸含量占62.74%;必需氨基酸(色氨酸除外)含量占39.02%,为幼儿所必需的半必需氨基酸(即精氨酸、组氨酸)含量占9.9%。

关键词: 芋艿分离蛋白, 等电点, 变性温度, 氨基酸组成, 相对分子质量

Abstract: Isoelectric point, denaturation temperature, amino acid composition, and molecular weight of taro protein isolates were studied in this paper. The results showed taro protein isolates had two main pI bands which near 6.73 and 5.21 accounted for 16.36% and 27.30% of the protein respesctively. SDS-PAGE analysis indicated that taro protein isolates are mainly composed of four subunits,which relative molecular weight distribution were about in 57 000, 46 300, 34 200 and 8 500 Da. A new band having about 23 100 Da molecular weight appeared with added mercaptoethanol. This proved taro protein isolates had the disulfide bonds between the subunits. DSC analysis confirmed that taro protein isolates denaturation temperature was 71.3±0.2℃, and denaturation enthalpy ΔH was 1.550 J/g. Amino acid analysis demonstrated that polar and nonpolar amino acid contents were 37.26% and 62.74% respectively. The contents of essential amino acids except tryptophan was 39.02% and that of semi-essential amino acids needed for growth of very young children was 9.9%.

Key words: taro protein isolates, isoelectric point, denaturation temperature, amino acid composition, molecular weight

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