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聚谷氨酸(PGA)和聚谷氨酸钠(PGA-Na)在不同的相对湿度(R H)下,用红外光谱仪测得它们的结构和侧链非离子化羧基的变化.固态PGA-Na(平均分子量[MW]8000),在50%R H以下能保持无规卷曲结构,在50—70%R H之间为β-折叠,70%R H以上为x-螺旋.以二氧六环:水二1.5:1(V/V)的混合液作为溶剂的PGA(MW8000)溶液,涂为膜后,在各种相对湿度下保持α-结构,但侧链非离子化羧基有变化,而且这种变化是可逆的.当PGA分散在水中成悬浮液后涂成的膜,在很宽的相对湿度范围内,保持α-螺旋不变,直至96%R H.才出现β-折叠,而且是不可逆的.
Polyglutamic acid (PGA) and polyglutamic acid (PGA-Na) were measured for their structure and changes of non-ionized carboxyl groups of the side chains by infrared spectroscopy at different relative humidity (RH) (Average molecular weight [MW] 8000), capable of maintaining a random coil structure at 50% RH or less, β-sheet between 50-70% RH and x-helix above 70% RH. Two 1.5: 1 (V / V) mixed solution as a solvent PGA (MW8000) solution, coated with a film, the α-structure maintained at various relative humidity, but the side chain non-ionized carboxyl changes, and this The change is reversible.When the PGA is dispersed in water and suspended in a solution, the membrane retains the α-helix in a wide range of relative humidity until β-sheeting occurs at 96% RH and is irreversible of.