Recombinant Human Semenogelin-2 (SEMG2)

A truncated version of Semenogelin-2/SEMG2 lacking the 1-23 amino-acid signal peptide of the C-terminus and carrying a 6xHis-tag at the N-terminus was produced in the yeast. The resulting protein is a full-length of mature SEMG2 protein. It contains aa of 24-582 of the human SEMG2 protein. It was purified by SDS-PAGE and reached up to 90% in purity. On the reducing SDS-PAEG gel, this SEMG2 protein migrated on the molecular weight band of about 65 kDa. The result is slightly higher than that of the calculated one due to glycosylation. This recombinant SEMG2 protein may be used to produce specific antibodies or on the SEMG2-associated signal transduction. SEMG2 also referred to as SgII, is secreted by the seminal vesicles. Together with SgII and fibronectin, SEMG2 is involved in the formation of the coagulum formed by newly ejaculated human semen. Upon semenogelins' proteolysis by prostate-specific antigen (PSA), the sperm coagulum was liquefied within 5-20 minutes and released the trapped spermatozoa and accessory gland secretions. Besides, SEMG2 interaction with transglutaminase and activation to sperm hyaluronidase shows that it also participates in the degradation of the envelope around the ovum during fertilization.