Preparation Of OSMIP@Silica Gel And Its Mechanism In Screening Lead Compounds Of Neuraminidase Inhibitor

Molecularly imprinting technology(MIT),which simulates the specific interaction between enzyme and substrate,is employed to prepare the polymers with recognition sites of predetermined specificity to target compound or template molecular.Molecularly imprinted polymers(MIPs)with the enzyme inhibitor as template could be used to simulate enzyme activity center to screen lead compounds.In present research,oseltamivir,which is a prodrug of influenza virus neuraminidase(NA),was employed as template to prepare MIP to simulate NA activity center.It was used to research the feasibility and mechanism of screening lead compounds by MIT.1.Silica gel coated with an MIP layer for OS(OSMIP@silica gel)was successfully prepared.The obtained particles were characterized through FT-IR,elemental analysis,scanning electron microscopy,specific surface area analysis,and porosity measurements.The results indicated that the polymer was uniform spherical porous particles and revealed the structural differences between imprinted and nonimprinted polymers.2.OSMIP@silica gel was packed into liquid chromatographic(LC)column.The specific affinity of the OSMIP@silica gel LC column for OS and other compounds were investigated by LC-MS online.The chromatographic performance of the OSMIP@silica gel column for OS had significant improvement.OSMIP@silica gel column showed good affinity for template OS and another neuraminidase inhibitor peramivir,as well as berberine hydrochloride,palmatine hydrochloride and trimethoprim(TMP),but not for acyclovir,dithranol,aspirin eugenol ester,aspirin and quinocetone.3.The results of static adsorption experiments showed that OSMIP@silica gel had specific adsorption sites for OS,and other affinitive compounds peramivir,berberine hydrochloride,palmatine hydrochloride and TMP,but not for quinocetone.Thermodynamic test results show that absorption of OSMIP@silica gel for OS was preferential adsorption.4.In vitro,OS acid has good inhibitory activity for NA.The affinitive compound peramivir,which is NA inhibitor as positive control,berberine hydrochloride and palmatine hydrochloride also have good activity against NA in vitro.Non-affinity compounds acyclovir,aspirin eugenol ester and quinocetone did not have the related activity.However,affinitive compound TMP did not have the related activity too.5.The results of molecular docking showed that active compounds berberine hydrochloride and palmatine hydrochloride could form a strong interaction with residue Asp 151 in NA activity center as well as OS acid and peramivir.The results also showed that TMP,inactive compounds and their analogues could not form effective interaction with the center.6.Results of surface plasmon resonance showed that template OS and positive control OS acid and peramivir have strong interaction with NA.Berberine hydrochloride and palmatine hydrochloride could also form the medium interaction with NA.TMP and other compounds just had weak interaction with NA.In conclusion,the compounds,which had affinity with OSMIP@silica gel column,could be absorbed specifically by OSMIP@silica gel.The compounds with good affinity had activity against NA in vitro,but TMP was a false positive result.The compounds with good affinity and activity could form a strong interaction with residue Asp 151 in NA activity center as well as OS acid and peramivir,and have medium interaction with NA.The above results showed that the structure of affinity compounds may be quite different from that of template molecules,but it may have the same activity in vitro and mechanism.The research might improve the drug screening theory based MIT to some extent.