MOF Nanofluorescent Probes Are Used For Phosphorylation/pH Detection And Imaging In Disease Processes

Proteins and bioactive small molecules are important for maintaining normal life activities of the human body.Protein post-translational modification plays an important role in regulating protein function and is involved in almost all processes of life.Protein phosphorylation is the most common and basic mechanism to regulate the properties and functions of proteins.Bioactive molecules such as H~+play an important role in maintaining the acid-base balance of human body,regulating life activities and maintaining physiological health,and are closely related to the development and occurrence of diseases.Therefore,the study of protein phosphorylation level and pH change in the process of disease is of great significance for understanding the mechanism of disease,diagnosis and drug screening.Based on this,two types of nanofluorescence probes were constructed based on the metal-organic framework(MOF)to achieve the ratio fluorescence imaging of protein phosphorylation level and the simultaneous detection and imaging analysis of protein phosphorylation level and pH,respectively.Combined with two-photon imaging,the probe was successfully used for in situ fluorescence imaging of protein phosphorylation levels in atherosclerotic rats and in vivo fluorescence imaging of protein phosphorylation levels and pH levels in colitis mouse models.This study provides a new method for revealing phosphorylation and ph-related signaling pathways to explore the mechanism of disease.The specific work is as follows:1.Using zirconium metal ions as the active center,porphyrin molecules and fluorescent nanoclusters wool-balls as fluorophores,a fluorescent probe for protein phosphorylation recognition ratio was constructed to achieve the imaging analysis of protein phosphorylation ratio in atherosclerotic rats.The specific recognition of phosphorylation sites is achieved by the specific interaction between the active center Zr(IV)and phosphoric acid.A ratio-type nanoprobe for specific recognition of phosphoric acid is constructed by using the FRET principle of porphyrin molecules and fluorescence nanoclusters called wool-balls.The morphology and elemental composition of the materials were characterized by DLS,TEM,XPS and XRD.The biocompatibility of the probe was improved by modifying the surface of the probe with BSA.Finally,by two-photon imaging fluorescence probe has been successfully applied in atherosclerosis rat protein phosphorylation level of fluorescence imaging,the results found that atherosclerosis rats protein phosphorylation levels are lower than normal rats,the study in order to further reveal the phosphorylation pathway mechanism provides a new analysis method and related diseases.2.The change of intestinal pH is closely related to the occurrence of enteritis,while the abnormal protein phosphorylation level is related to the occurrence and development of inflammation.Based on this,we constructed a MOF-based nano-fluorescence sensor,PCN-NP-HPZ,to achieve simultaneous detection and imaging analysis of pH level and phosphorylation level.Using Zr(IV)as a metal node,PCN-NP-HPZ realized the detection of phosphorylation level through the specific coordination between zirconium and phosphoric acid,combined NP-HPZ with MOF through supramolecular interaction,and realized the specific detection of H~+through ph-sensitive piperazine group.The recognition performance of phosphorylation site and pH by nano-sensor was studied by fluorescence.Finally,the fluorescence probe was successfully applied to in vivo fluorescence imaging of phosphorylation and pH levels in colon and detection of phosphate and pH levels in blood in a mouse model of colitis.This study provides a new method for clinical evaluation of colitis disease.