Abstract: The present invention relates to a method for detecting a substance having an activity to inhibit HIV infection rapidly, economically and safely. The present invention uses the characteristics that if a function of transmembrane protein gp41 of HIV is inhibited, HIV infection is also inhibited, and therefore the function of gp41 depends on the interaction between two helical structures of gp41. The method of the present invention is to detect a substance to inhibit HIV infection by an immunoassay using the interaction between the variant protein Trx-N, which is prepared by binding the N-terminal helical domain of gp41 to Trx (thioredoxin) and the variant protein GST-C, which is prepared by binding the C-terminal helical domain of gp41 with GST-C (Glutathione S-transferase). This immunoassay can be used for automatic detection of the substance to inhibit the activity of gp41 can be carried out by the method.

Abstract: Gene sequences of superoxide dismutase of Aquifex pyrophilus which is one of hyperthermophile microorganism and protein expressed therefrom are provided, wherein the protein is used as a necessary medicament in treatment of inflammation, disease of autoimmunization, chromosome lesion and the like, and particularly, A. pyrophilus is a hyperthermophile which can grow at the optimum temperature of 85.degree. C., and thus the superoxide dismutase of A. pyrophilus has a higher thermal stability than other organisms, resulting in further broad applications in the pharmaceutical field.