Modeling In Vitro Hyaluronan Synthesis by Non-processive Enzymes

The giant biopolymer Hyaluronan (HA) is commonly synthesized in the membrane of living cell by highly processive enzymes. Given hyaluronan’s use as a medial lubricant, cosmetic ingredient, and treatment for joint pain there has been significant research aimed at gaining control over hyaluronan size and polydispersity during lab-based synthesis to optimize the physical and therapeutic properties of the synthesised material. Of note in this work, is the ability of synthesis enzyme from the bacterium P. multocida to catalyze HA synthesis in a non-processive manner during in vitro reactions [1]. When reactions are seeded with short HA primers this enzyme has demonstrated the ability to produce a highly monodisperse product. While this behavior has been qualitatively attributed to the strong preference for extension of existing product over the formation of new product, there is no quantitative model that explains this behavior. I present kinetic models that describe these in vitro synthesis reactions. Simulation of the reactions allows investigation of the systems’ behavior under a wide range of conditions, including prediction of reaction outcomes. Conditions that reproduce the behavior observed in previous experiments are identified and the results will support ongoing investigations into more complex one-pot synthesis schemes for HA.

[1] Jing, Wei, and Paul L. DeAngelis. Journal of Biological Chemistry 279, no. 40 (2004): 42345-42349.