蛋白质结构与功能范例.ppt

20种氨基酸中哪种分子量最小？ 哪些氨基酸是支链氨基酸？ 哪些氨基酸是芳香族氨基酸？ 哪些氨基酸是杂环氨基酸？ 哪些氨基酸是羟基氨基酸？ 哪些氨基酸是含酰胺基氨基酸？ 哪些氨基酸是含硫氨基酸？ 哪些氨基酸是酸性氨基酸？ 哪些氨基酸是碱性氨基酸？ 哪个氨基酸是亚氨基酸？ 哪些氨基酸是非极性、疏水性氨基酸？ 哪些氨基酸是极性、中性氨基酸？ Gly Val, Leu, Ile Phe, Tyr, Trp Pro, His, Trp Ser, Thr, Tyr Asn, Gln Cys, Met Asp, Glu Arg, Lys, His Pro 生化词汇 1. 蛋白质变性 protein denaturation 2. 谷胱甘肽 GSH 3. α-螺旋 α-helix 4. 等电点 Isoelectric point( pI) 5. β-折叠 β-pleated sheet 思考题: 1.蛋白质的元素组成、基本组成单位， 氨基酸成肽的连接方式；熟悉氨基酸的通式与结构特点；氨基酸三字母英文缩写。 2.蛋白质1~4级结构的定义及维系这些结构稳定的作用键 3.蛋白质二级结构的基本形式？ 4.举例说明蛋白质一级结构与功能的关系。 5.什么是蛋白质的变性？哪些因素可引起蛋白质的变性？变性蛋白质的性质发生了哪些变化？ 1．血清某一蛋白（pI为7.0）在下列哪种pH值溶液 中带负电荷？( ) A．pH4.0 B．pH5.0 C．pH6.0 D．pH7.0 E．pH8. 0 2．维系蛋白质二级结构稳定的化学键是( ) A．盐键 B．二硫键 C．氢键 D．疏水键 E．肽键 测试题 Summary Proteins are linear polymers that are synthesized from the same 20 L-α-amino acids, linked by peptide bond. All these amino acids have a carboxyl group and an amino group attached to the α C atom. The various amino acids are usually classified according to the polarities of their side chains---R, no polar, uncharged and polar, charged and polar amino acids. ◆Primary structure: the amino acids sequence of the polypeptide chain . Stabilizing force: peptide bond; disulfide bond ◆Secondary structure: the conformation of the polypeptide backbones of proteins. Stabilizing force: hydrogen bonds Four kinds: ?-helix、?-pleated sheet 、?-turn、random coil Protein Structure: Primary, Secondary, Tertiary, Quaternary structure The relationship of structure and function of a protein: The primary structure is the base of special conformation，special conformation determines a protein function. The physical and chemical properties of proteins: Dipolar ion and pI ; denaturation Gel characters( hydrate shell, charges) Ultraviolet absorption(280nm) * * 蛋白质的结构 按组成成分： 单纯蛋白（仅含氨基酸） 结合蛋白（单