Patents by Inventor Richard Honzatko

Richard Honzatko 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).

  • Protein engineering of glucoamylase to increase pH optimum, substrate specificity and thermostability
    Patent number: 6537792
    Abstract: A fungal glucoamylase including a mutation pair Asn20Cys coupled with Ala27Cys forming a disulfide bond between the two members of the pair. The mutation provides increased thermal stability and reduced isomaltose formation to the enzyme. A fungal glucoamylase including a 311-314Loop mutation wherein reduced isomaltose formation is provided by the mutation is also provided. A fungal glucoamylase including a mutation Ser411Ala wherein increased pH optimum and reduced isomaltose formation is provided by the mutation is also provided. Combinations of the mutations in engineered glucoamylases are also provided as are combinations with other glucoamylase mutations that provide increased thermal stability, increased pH optimum and reduced isomaltose froamtion for cumulative improvements in the engineered glucoamylases. Also provided is a fungal glucoamylase including a mutation of Ser30Pro coupled with at least two stabilizing mutations forming a disulfide bond between the two stabilizing members.
    Type: Grant
    Filed: January 22, 1999
    Date of Patent: March 25, 2003
    Assignee: Iowa State University
    Inventors: Martin J. Allen, Tsuei-Yun Fang, Yuxing Li, Hsuan-Liang Liu, Hsiu-Mei Chen, Pedro Coutinho, Richard Honzatko, Clark Ford