Arg¹⁵-Lys¹⁷-Arg¹⁸ Turkey Ovomucoid Third Domain Inhibits Human Furin. Lu, W., Zhang, W., Molloy, S., Thoms, G., Ryan, K., Chiang, Y., Anderson, S. and Laskowski, M., Jr. (1993) The Journal of Biological Chemistry, 268, 14583-14585.

Abstract

Turkey ovomucoid third domain with Leu¹⁸ in its reactive site is a potent inhibitor of many serine proteinases: subtilisins, chymotrypsins, and elastases. Previous studies showed that an L18K mutation make it a moderately strong inhibitor of trypsin, while an L18E mutation made it a strong inhibitor of Glu-specific Streptomyces griseus proteinase (GluSGP). For hman furin substrates the consensus optimal sequence is RXKR. Therefore the A15R, T17K, and L18R mutations were made in turkey ovomucoid third domain. The mutant inhibits human furin with a K_a of 1.1 x 10⁷ M^-1. As human furin catalyzes an obligatory step in human immunodeficiency virus proliferation, this inhibitor, along with the others already available, deserves further study.