2,5-di-[2-(3,5-bis(2-pyridylmethyl)amine -4-hydroxy-phenyl) ethylene] pyrazine zinc complex as fluorescent probe for labeling proteins.
The binding characteristics between 2,5-di-[2-(3,5-bis(2-pyridylmethyl)amine -4-hydroxy-phenyl) ethylene] pyrazine (1) or its complex (1-Zn) and serum albumins were studied by fluorescence spectroscopy in pH 7.4 aqueous solution. 1-Zn emitted weak fluorescence at 580 nm in a pH 7.4 Tris-HCl buffer solution when excited at 435 nm, however, the fluorescence intensity increased upon addition of serum albumins with the blue shift of emission peak to 524 nm. The binding constants were estimated as 8.40 x 10(7) and 3.03 x 10(6)mol(-1)L for bovine serum albumin (BSA) and human serum albumin (HSA) respectively, and the number of binding sites was 1 for each. The quenching mechanism of fluorescence of serum albumins by 1-Zn was considered as a static quenching process. The binding distance between 1-Zn and serum albumins and the energy transfer efficiency were obtained based on the theory of Förester spectroscopy energy transfer. The effect of 1-Zn on the conformation of serum albumins was further analyzed using synchronous fluorescence spectrometry. The experiment results clearly showed that 1-Zn is a highly sensitive protein sensor.
Department of Chemistry, Nanchang University, Nanchang 330047, China. fywu@ncu.edu.cn
Fang-Ying
FY
Wu
Fei-Yan
FY
Xie
Yu-Mei
YM
Wu
Jong-In
JI
Hong
D000818:Animals; D001665:Binding Sites; D002417:Cattle; D005456:Fluorescent Dyes / Q000032:analysis* / Q000737:chemistry*; D006801:Humans; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000032:analysis* / Q000737:chemistry*; D012709:Serum Albumin / Q000032:analysis* / Q000737:chemistry*; D013050:Spectrometry, Fluorescence; D017186:Titrimetry
C528474:2,5-di-(2-(3,5-bis(2-pyridylmethyl)amine-4-hydroxy-phenyl)-ethylene)-pyrazine-Zn; D005456:Fluorescent Dyes; D009942:Organometallic Compounds; D012709:Serum Albumin