Akashi S, Niitsu U, Yuji R, Ide H, Hirayama K
Central Research Laboratories, Ajinomoto Co. Inc., Kawasaki, Japan.
Biol Mass Spectrom. 1993 Feb;22(2):124-32. doi: 10.1002/bms.1200220205.
The interaction between enzyme and its inhibitor, hen egg-white lysozyme and tri-N-acetylglucosamine (NAG3), was studied by the combination of chemical modification, enzymatic digestion, electrospray ionization mass spectrometry and frit-fast atom bombardment liquid chromatography/mass spectrometry. Chemical modification of amino groups, carboxyl groups, and indole groups was carried out independently. In the absence of NAG3, the carboxyl group in Asp 101 was modified by glycinamidation, and the indole group in Trp 62 was modified by Koshland reagent. In the presence of NAG3, the degree of modification of Asp 101 and Trp 62 decreased. It is suggested that Asp 101 and Trp 62 are involved in the interaction with NAG3. The result is consistent with the one obtained by x-ray crystallography. It is indicated that the combination of chemical modification and mass spectrometry may be effective for the investigation of the binding reaction of enzyme to inhibitor and of protein-protein interaction.
通过化学修饰、酶消化、电喷雾电离质谱和快原子轰击液相色谱/质谱联用技术，研究了酶及其抑制剂——鸡蛋清溶菌酶和三-N-乙酰葡糖胺（NAG3）之间的相互作用。分别对氨基、羧基和吲哚基进行了化学修饰。在不存在NAG3的情况下，通过甘氨酰胺化修饰了Asp 101中的羧基，并用科什兰德试剂修饰了Trp 62中的吲哚基。在存在NAG3的情况下，Asp 101和Trp 62的修饰程度降低。提示Asp 101和Trp 62参与了与NAG3的相互作用。该结果与通过X射线晶体学获得的结果一致。表明化学修饰和质谱联用可能对研究酶与抑制剂的结合反应以及蛋白质-蛋白质相互作用有效。
