Patent 7399839 was granted and assigned to Bolder Biotechnology on July, 2008 by the United States Patent and Trademark Office.
The present invention relates to novel methods of making soluble proteins having free cysteines in which a host cell is exposed to a cysteine blocking agent. The soluble proteins produced by the methods can then be modified to increase their effectiveness. Such modifications include attaching a PEG moiety to form pegylated proteins.