Patents by Inventor Xianxing Du

Xianxing Du has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Coding sequence for protein phosphatase methylesterase, recombinant DNA molecules and methods
    Patent number: 6232110
    Abstract: Carboxymethylation of proteins is a highly conserved means of regulation in eukaryotic cells. The protein phosphatase 2A (PP2A) catalytic (C) subunit is reversibly methylated at its carboxy-terminus by specific methylesterase. Carboxymethylation affects PP2A activity and varies during the cell cycle. The present disclosure provides the coding sequence of a methylesterase, herein named Protein Phosphatase Methylesterase-1 (PME-1). PME-1 is highly conserved from yeast to human and contains a motif found in lipases, which motif has a catalytic triad-activated serine as the active site nucleophile. Recombinant PME-1 polypeptide produced in bacteria demethylates PP2A C subunit in vitro and okadaic acid, a known inhibitor of the PP2A methylesterase, inhibited this reaction. PME-1 represents the first mammalian protein phosphatase methylesterase cloned to date.
    Type: Grant
    Filed: April 16, 1999
    Date of Patent: May 15, 2001
    Assignee: Emory Univeristy
    Inventors: David C. Pallas, Xianxing Du