ABSTRACT
Objective To screen cardiac-specific short-acting peptides on live myocardial slices using phage display technology,so as to improve the targeted delivery efficiency of drugs in myocardium and provide effective candidates for the targeted therapy of Duchenne muscular dystrophy (DMD) and other cardiomyopathies.Methods Myocardial tissue slices were prepared and cultured in vitro.The protein activities of the tissues were examined by immunohistochemistry.The in vitro cultured myocardial tissue slices were co-incubated with phage library (1×1012 pfu),and the phages that bound to the myocardium were recovered and amplified.The cardiac-specific targeting phages were identified by five rounds of in vitro phage biopanning.The candidate phage-related insertion sequence was sequenced,and the in vivo tissue distribution of the highly enriched phages was verified.Results A platform for in vitro culturing of live myocardial slices was established.Myocardial slices with good biological activity were obtained.After 48 hours of culturing,the normal expression and localization of Dystrophin protein were detected.Using phage library,candidate phages were screened after five rounds of phage biopanning.The results of the sequencing analyses and in vivo tissue distribution verification indicated that the selected candidate phages showed significant enrichment in myocardium and skeletal muscle,and showed low levels in liver and kidney tissues.Conclusions The candidate phages showed higher binding efficiency in both myocardium and skeletal muscle,indicating that the candidate peptides had myocardial targeting property,and that can provide a new method for myocardial targeting therapy of DMD.
ABSTRACT
Objective To analyze the specific peptide of cystatin C (CysC) and its characteristics by bioinformatics technology,and verify the predicted results by mass spectrometry.Methods Online software was applied to analyze the physicochemical properties and homology of CysC peptides hydrolyzed by trypsin and predict the associated parameters of ionized fragmentation of specific peptide by mass spectrometry.Precursor ion scan and product ion scan were conducted on the samples of synthetic specific peptide.The recombinant human CysC and serum samples were analyzed by mass spectrometry after trypsin digestion.The results of analysis were compared with the outcomes predicted by bioinformatics.Results T3 (ALDFAVGEYNK) was considered as the specific peptide of CysC by software analysis.When selecting[M + 2H] 2 + for product ion scan,almost all the y and b ions of fragmentation were observed using tandem mass spectrometry (MS/MS),showing consistency with Skyline predictions.Moreover,both the peptides from the human recombinant CysC and serum sample following the trypsin digestion were eluted at the same time with the isotope-labeled T3 * under the fixed conditions.Conclusion Bioinformatics technology could be available for picking out the specific peptides of target protein quickly and efficiently and predicting the ionized fragmentation precisely by mass spectrometry scanning.