Gabellieri E, Strambini G B
CNR, Istituto di Biofisica, Pisa, Italy.
Biophys Chem. 1989 Jul;33(3):257-64. doi: 10.1016/0301-4622(89)80027-4.
The phosphorescence spectra of Trp-84 and Trp-310 in glyceraldehyde-3-phosphate dehydrogenase from Bacillus stearothermophilus in an aqueous glass show distinct 0,0 vibrational bands with peaks at 406.5 and 410.5 nm. With the aid of external heavy-atom perturbation of iodide and the thermal quenching profile, it is concluded that although both chromophores are effectively buried, only one, viz., the 406.5 nm component, is embedded in a sufficiently rigid core of the protein to phosphoresce in fluid solutions at room temperature. From inspection of the crystallographic structure is it evident that only Trp-310 embedded in the beta-sheet of the catalytic domain may satisfy the requirements of a long triplet-state lifetime and slow migration of O2 to its site. This identification confirms previous analysis of the phosphorescence properties of the enzymes from yeast, pig and rabbit muscle.
嗜热脂肪芽孢杆菌磷酸甘油醛脱氢酶中色氨酸-84和色氨酸-310在水玻璃中的磷光光谱显示出明显的0,0振动带，其峰值分别在406.5纳米和410.5纳米处。借助碘化物的外部重原子扰动和热猝灭曲线，可以得出结论：尽管两个发色团都被有效地包埋，但只有一个，即406.5纳米的组分，被嵌入到蛋白质足够刚性的核心中，从而在室温下的流体溶液中产生磷光。通过检查晶体结构可以明显看出，只有嵌入催化结构域β-折叠中的色氨酸-310可能满足长三重态寿命和氧气缓慢迁移到其位点的要求。这一鉴定结果证实了先前对酵母、猪和兔肌肉中该酶磷光特性的分析。
