Hyaluronic Acid and Its Synthases—Current Knowledge
Klaudia Palenčárová, Romana Köszagová, Jozef Nahálka
Abstract
Hyaluronic acid (HA) is a linear heteropolysaccharide that naturally occurs in vertebrates. Thanks to its unique physico-chemical properties, it is involved in many key processes in living organisms. These biological activities provide the basis for its broad applications in cosmetics, medicine, and the food industry. The molecular weight of HA might vary significantly, as it can be less than 10 kDa or reach more than 6000 kDa. There is a strong correlation between variations in its molecular weight and bioactivities, as well as with various pathological processes. Consequently, monodispersity is a crucial requirement for HA production, together with purity and safety. Common industrial approaches, such as extraction from animal sources and microbial fermentation, have limits in fulfilling these requests. Research and protein engineering with hyaluronic acid synthases can provide a strong tool for the production of monodisperse HA. One-pot multi-enzyme reactions that include in situ nucleotide phosphate regeneration systems might represent the future of HA production. In this review, we explore the current knowledge about HA, its production, hyaluronic synthases, the most recent stage of in vitro enzymatic synthesis research, and one-pot approaches.