In-vitro evaluation of a human recombinant iduronate-2sulfatase produces in the yeast Komagataella phaffii

Mucopolysaccharidosis type II (MPS II), also known as Hunter syndrome, is an X-linked disorder that produces a multisystemic condition and, in the most severe cases, generates damage to the Central Nervous System (CNS). This disorder is caused by the mutation in the IDS gene and with it the deficiency in the production of the enzyme Iduronate-2-Sulfatase (EC 3.1.6.13 - IDS), ad leading to the accumulation of the glycosaminoglycans (GAGs) heparan sulfate and dermatan sulfate in lysosomal compartments. Enzyme Replacement Therapy (ERT) is used as a treatment for MPS II, which decreases GAG levels and has significant clinical impacts. Nevertheless, this ERT has some access restrictions due, in part, to the high cost associated. In this study, we describe the characterization of a recombinant IDS produced in the yeast K. phaffii using fibroblast from an MPS II patient. For the production of the IDS enzyme, Komagataella phaffii GS115 strain was generated with a yeast-optimized cDNA of human IDS gene. Recombinant enzyme was purified from the culture medium by ion-exchange chromatography, obtaining a final activity of 7.33 U/mg. Cell uptake in MPS II fibroblasts showed concentration depended capture of the enzyme. Nevertheless, at 200 nM a lower enzyme uptake was observed suggesting a receptor saturation. We observed that untreated MPS II fibroblasts have a 2-fold increase in GAGs concentration compared to wild-type cells. This GAGs concentration was significantly reduced after treatment with 50 and 100 nM of the enzyme. Noteworthy, GAGs levels were normalized after 100 nM treatment. The results obtained allow establishing a precedent for the significant reduction of GAGs at a concentration using a yeast with an optimized cDNA sequence as an expression system, allowing a baseline to be generated for future research that ends in the development of a treatment for MPS II with low production cost.