Abstract: Provided is an antibody or a fragment thereof, which can be specifically bound to an S3-4 ring of a voltage sensor paddle of a domain III of voltage-gated sodium channel Nav1.9 ? sub-unit, and is able to inactivate a voltage sensor valve to keep sodium ions from entering nerve cells normally. Also provided is an epitope polypeptide specifically bound to the antibody or the fragment thereof, a pharmaceutical composition comprising the antibody or the fragment thereof, and a use of the antibody or the fragment thereof in preparing a drug for treating and diseases related to pains.

Abstract: The present invention provides an antibody or antibody fragment thereof for a targeted cytomembrane voltage-gated sodium channel ? subunit Nav1.9. The specific binding target is a S3-4 ring of a voltage sensor paddle of a domain II of the voltage-gated sodium channel ? subunit. The antibody or antibody fragment thereof is able to inactivate a voltage sensor valve, to make sodium ions unable to enter nerve cells normally, thereby achieving the effect of treating and relieving pains.