Hyaluronan synthases and methods of making and using same

A functionally active hyaluronan synthase having an amino acid sequence as set forth in at least one of SEQ ID NOS:15–29.

A method of providing a functionally active hyaluronan synthase having an altered enzymatic activity as compared to a corresponding functionally active native hyaluronan synthase, comprising the steps of:

• providing a hyaluronan synthase as set forth in SEQ ID NO:2;
• and
• modifying at least one cysteine residue of the hyaluronan synthase to an alanine or serine residue to provide a functionally active hyaluronan synthase having an altered enzymatic activity.

A method for producing hyaluronic acid, comprising the steps of:

• providing a host cell having at least one expression construct comprising a hyaluronan synthase gene encoding a functionally active hyaluronan synthase incorporated therein such that the host cell is capable of producing hyaluronan, wherein the functionally active hyaluronan synthase has an altered enzymatic activity as compared to a corresponding functionally active native hyaluronan synthase, wherein the corresponding functionally active native hyaluronan synthase is seHAS, and wherein the functionally active hyaluronan synthase has at least one modified amino acid residue therein as compared to a corresponding functionally active native hyaluronan synthase, and wherein the at least one modified amino acid residue is a cysteine modified to an alanine or a serine residue;
• and
• culturing the host cell under conditions appropriate for the production of hyaluronic acid.

A functionally active hyaluronan synthase having at least one modified amino acid residue therein as compared to a corresponding functionally active native hyaluronan synthase, wherein the corresponding functionally active native hyaluronan synthase is seHAS, and wherein the at least one modified amino acid residue is a cysteine modified to an alanine or a serine residue, and wherein the functionally active hyaluronan synthase has an amino acid residue as set forth in at least one of SEQ ID NOS:15–29.

A functionally active hyaluronan synthase having an altered enzymatic activity as compared to a corresponding functionally active native hyaluronan synthase, wherein the corresponding functionally active native hyaluronan synthase is seHAS, and wherein the functionally active hyaluronan synthase has at least one modified amino acid residue therein as compared to a corresponding functionally active native hyaluronan synthase, and wherein the at least one modified amino acid residue is a cysteine modified to an alanine or a serine residue.

A functionally active hyaluronan synthase having at least one modified amino acid residue therein as compared to a corresponding functionally active native hyaluronan synthase, wherein the corresponding functionally active native hyaluronan synthase has an amino acid sequence as set forth in SEQ ID NO:2, wherein the at least one modified amino acid residue is a cysteine, and wherein the cysteine is modified to an alanine or a serine residue.

A functionally active hyaluronan synthase having an altered enzymatic activity as compared to a corresponding functionally active native hyaluronan synthase, wherein the corresponding functionally active native hyaluronan synthase has an amino acid sequence as set forth in SEQ ID NO:2, wherein the functionally active hyaluronan synthase has at least one modified amino acid residue therein as compared to a corresponding functionally active native hyaluronan synthase, and wherein the at least one modified amino acid residue is a cysteine modified to an alanine or a serine residue.