天花粉凝集素的荧光光谱研究

天花粉凝集素在天然状态下荧光发射峰位于３３２ｎｍ处，以丙烯酰胺，ＫＩ及ＣｓＣ１等淬灭剂研究ＴＫＬ分子中Ｔｒｐ残基的微环境，发现只有丙烯酰胺能淬灭ＴＫＬ分子Ｔｒｐ的荧光，同此推断大部分的Ｔｒｐ残基位于ＴＫＬ分子内部，其荧光不易为Ｉ＾－或Ｃｓ＾＋接近而淬灭。疏水探针ＴＮＳ能够检测到ＴＫＬ中疏水微区的存在，并且这一疏水微区亦不同于ＴＫＬ的半乳糖结合位点，ＴＫＬ中不存在金属离子的结合部位。

Study of Trichosanthes kirilowii Lectin by Fluorescence Spectroscopy

In native conditions,the maximum peak in the emission spectrum of Trichosanthes kirilowii lectin(TKL)was at 332 nm. To study the micro-environment of tryptophanyl residues in TKL molecule,acrylamide,KI and CsCl were used to quench the fluorescence of TKL.Results showed that only acrylamide could partially quench the fluorecence of TKL while KI and CsCl could not.Thus we deduced that most of the Trp residues were located in the inner core of TKL molecule,probably in the hydrophobic area.Hydrophobic area was detected to be present,in TKL by the interaction with fluorescene probe TNS,and this hydrophobic area was different from the galactose binding site of TKL.There was no evidence to show metal-binding site in TKL moleclule.