Autodisplay of human hyaluronidase hyal-1 and identification of new inhibitors among natural compounds

Orlando Z, Olschewski I, Brossette T, Hensel A, Jose J

Abstract

Hyaluronan (HA) is a linear biopolymer and the main component of the extracellular matrix. Its metabolism plays a crucial role in physiological and pathophysiological processes. It is generally accepted that thedepolymerization of HA to oligomeric chains influences various cellular processes such as proliferation, differentiation, inflammation, angiogenesis and metastasis [1]. Hyaluronidases are enzymes that catalyze thedegradation of HA. This makes hyaluronidases an interesting pharmaceutical target for a new option of anti-tumor and anti-inflammation treatment. Due to the formation of ‘‘inclusion bodies’’ in prokaryotic cytoplasmthe attempt of using the well-known organism Escherichia coli to produce catalytically active human hyaluronidase Hyal-1 remains a major challenge, yet [2]. In this work, we overcome this difficulty by applying theAutodisplay technology. Thereby hHyal-1 was expressed as a part of an autotransporter fusion protein on the cell surface of E. coli. Based on this technology we developed a whole cell activity assay using the dye‘‘stains-all’’ [3]. With this assay we screened a library of natural compounds and plant extracts and identified three saponin derivatives and four plant extracts to l inhibit human Hyal-1.