The Research Of 3-hydroxyflavons As Protein ?-helix Structures Fluorescent Probe

To be able to perform their biological function,protein fold into one or more specific spatial conformations,driven by a number of non-covalent interactions such as hydrogen bonding,ionic interactions,Van der Waals forces,and hydrophobic packing.To underatand the functions of proteins at a molecular level,it is often necessary to determine their three-dimensional structure.Protein secondary structure,which is formally defined by the pattern of hydrogen bonds of protein(such as alpha helices and beta sheets)that are observed in an atomic-resolution structure,is the general three-dimensional form of local segments of proteins.Untile now,a serial of methods have been reported to detect it.However,there are still limitations with these them,such as time comsuming,complicate sample treatment and so on.Fluorescence-based assays could be useful in this field because of their high sensitivity and convenience.However,fluorescence methods for protein secondary structure detection,especially for real-time detection in biological samples,are still very limited so far.In our previous work,we found that a-helical structures of protein enhanced the excited-state intramolecular proton transfer(ESIPT)process of some fluorescent mocecules which was applied it to modification of a series of 3-hydroxyflavones scaffold fluorescent molecular and studier their responses towards proteins containinga-helical structure,and results showed that these probes were more sensitive towards protein a-helical structure,along with longer stock shift.The fluorescence intensity of these compounds also changed during the binding of calmodulin with Calcium,which suggest that these fluorescent probes could also be potentially used to discriminate proteins with differenta-helical content change.Furthermore,we found a strong interaction between fluorescence probes and probes consisting high?-helical content,which may be used to prevent the fluorescent probe escaping from cell membrance,and thus improve the intracellular retention of these fluorescent molecules.In deed,it was proved by fluorescence microscopy and flow cytometry study.In deed,it was proved by fluorescence microscopy and flow cytomerty study.It also revealed the potency of these molecules as parent molecule for long time monitoring fluorescent probes.