The Study of Selection, Structural Analysis and Specificity of Aptamers to Listeria Monocytogenes
|School||Fujian Normal University|
|Keywords||Mononuclear Listeria SELEX Aptamer PCR Binding rate Specificity|
In this paper, the exponential enrichment ligand system evolution (SELEX) technology mononuclear Listeria (Listeria monocytogenes) aptamer screening , designed to filter out bacteria has a high affinity for specific binding of DNA aptamer monocytogenes in food detection of Listeria lay a certain foundation . In the the SELEX process of in vitro screening of Listeria monocytogenes , the use of the the reverse screening technique to remove the presence of Listeria monocytogenes shared epitope antigen to accelerate specific table of Listeria monocytogenes bit antigen aptamer enrichment process . After 14 screening , screening products for cloning , sequencing , and sequencing part of the aptamer primary structure and secondary structure analysis , the determination of the binding rate and specificity . SELEX screening results show that the upward trend in each round of the ssDNA enriched library monocyte Listeria binding rate , combined with the color after the absorbance value rose to 14 from a 0.264 0.659 increased nearly 2.5 times. A structurally conserved sequence shows exactly the same sequence of five pairs aptamer , another part of the aptamer sequence only one base , and the CCC (TG) C (G) GGG (CA) 12 bases in 11 fitness body have the sequence , which shows a structural homology of the aptamer with a certain degree of enrichment . Secondary Structure simulation diagram to stem cyclic structure described mainly about these stems cyclic structure is the basis of the aptamer with the target molecule binding , is further formed on the basis of the three dimensional structure . Aptamer with Listeria monocytogenes binding assay showed that , the B09 aptamer binding rate maximum, minimum rate of No. 127, the binding of the aptamer . B09 aptamer specificity experiments show that the maximum absorbance value in the binding of B09 aptamer monocytogenes Listeria , 0.760 ; B09 aptamer having a certain degree of specificity for subsequent applied research laid certain basis .