Our 3-Sec Technique For the Luminespib
Figure 5 Overlapping of fluorescence spectra of HAase (CHAase = 2.0 �� 10?6?mol?L?1) with absorption spectra of liquiritigenin (Cliquiritigenin = 2.0 �� 10?6?mol?L?1). In the present case, K2 = 2/3, n = 1.366, and �� = 0.118 [21]. According to (6)�C(8), the values of the parameters were calculated to be J = 1.899 �� 10?14?cm3?moL?1?L, E = 0.07, R0 = 3.23?nm, and r = 5.04?nm. The distance between liquiritigenin and HAase was obviously less than 7?nm and 0.5R0 SERCA Conformational Investigations In order to understand the possible effect of liquiritigenin binding on the secondary structure of HAase, the synchronous fluorescence and the three-dimensional fluorescence spectra were measured in the absence and presence of liquiritigenin. When the wavelength interval (����) between the excitation and emission wavelength is stabilized at 15 or 60?nm, the synchronous fluorescence gives characteristic information of tyrosine (Tyr) residues or tryptophan (Trp) residues, respectively [22, 23]. The synchronous click here fluorescence spectra at these two different wavelength intervals are presented in Figure 6. As the concentration of liquiritigenin increased gradually, the synchronous fluorescence intensity decreased; however, an obvious shift of the Tyr peak and Trp peak cannot be observed in Figures 6(a) and 6(b), which indicated that liquiritigenin has a weak effect on the microenvironment of Tyr and Trp residues in HAase. On the other hand, it can be seen from Figure 7 that the slope was higher when ���� was 60?nm, which indicated that liquiritigenin was closer to the Trp residues than to the Tyr residues and the microenvironments of Trp residues were influenced more Luminespib than those of Tyr residues. Figure 6 Synchronous fluorescence spectra of interaction between HAase and liquiritigenin at (a) ���� = 15?nm and (b) ���� = 60?nm at room temperature. Peak from up to down Cliquiritigenin = (0, 4.0, 8.0, 12.0, 16.0,20.0, ... Figure 7 The quenching of HAase synchronous fluorescence by liquiritigenin. CHAase = 2.0 �� 10?6?mol?L?1, (��) ���� = 15?nm and (��) ���� = 60?nm (n = 3). Three-dimensional fluorescence spectroscopy is a powerful method for providing conformational and structural information of proteins [24]. The three-dimensional fluorescence spectra of HAase and liquiritigenin-HAase systems are shown in Figure 8. It can be seen from Figure 8(a) that the three-dimensional fluorescence contour spectrum of HAase shows contour maxims at ��ex/��em = 278/330?nm arising by ��-��? transition of aromatic amino acids in HAase. In Figure 8(b), the HAase fluorescence peak shifted to 278/335?nm.
