Ueda T, Goda K, Mori T, Murakami E, Kotake Y
J Biochem. 1977 Jul;82(1):67-72. doi: 10.1093/oxfordjournals.jbchem.a131693.
An equimolar mixture of a xanthurenic acid-insulin complex and ZnSO4 was separated into an insulin peak and a peak containing xanthurenic acid (XA) and Zn by Sephadex G-75 column chromatograpy. XA and di-[L-histidino]-zinc (II) readily combined to produce di-[L-histidino]-di-xanthurenato zinc (II) (His2-Zn2+-XA2). By increase in the concentration of Zn2+ ions, XA was removed from di-[L-histidino]-di-xanthurenato zinc (II) (His2-Zn2+-XA2) as XA-Zn2+. The XA-insulin complex showed dcreased relative intensity of fluorescence compared with the Zn-insulin when excited at a wavelength of 284 nm. The difference spectrum between native Zn-insulin and XA-insulin complexes showed a slight red shift. A diffference in the CD spectrum between native Zn-insulin and XA-insulin complexes was observed.
通过葡聚糖凝胶G - 75柱色谱法，将黄尿酸 - 胰岛素复合物与硫酸锌的等摩尔混合物分离为胰岛素峰以及一个含有黄尿酸（XA）和锌的峰。XA与二 - [L - 组氨酸] - 锌（II）很容易结合生成二 - [L - 组氨酸] - 二 - 黄尿酸锌（II）（His2 - Zn2 + - XA2）。通过增加Zn2 +离子的浓度，XA以XA - Zn2 +的形式从二 - [L - 组氨酸] - 二 - 黄尿酸锌（II）（His2 - Zn2 + - XA2）中被去除。当在284nm波长激发时，与锌 - 胰岛素相比，黄尿酸 - 胰岛素复合物的荧光相对强度降低。天然锌 - 胰岛素和黄尿酸 - 胰岛素复合物之间的差示光谱显示出轻微的红移。观察到天然锌 - 胰岛素和黄尿酸 - 胰岛素复合物之间圆二色光谱的差异。
