Patents by Inventor John P. Markwell

John P. Markwell 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).

  • Publication number: 20030166518
    Abstract: Disclosed are methods for the characterization of allergens using recombinant fusion protein in an enzyme-linked immunosorbent (ELISA) assay. Also disclosed are methods for determining allergen sensitivity and methods for immunotherapy using the ELISA of the present invention.
    Type: Application
    Filed: January 12, 2001
    Publication date: September 4, 2003
    Inventors: Thomas A. Beardslee, Michael G. Zeece, Guatam Sarath, John P. Markwell
  • Patent number: 5866406
    Abstract: To provide increased levels of oxidase, mutants of Aspergillus niger that constitutively synthesize glucose oxidase when grown in a medium having less than 0.1M (molar) glucose are obtained. To obtain mutants, a microorganism is cultured with a substrate having a nutrient, an auxiliary carbon source and a pH-sensitive indicator; and cultures in which the pH has changed as indicated by the pH-sensitive indicator are selected for further growth. More specifically, Aspergillus niger that has been subjected to mutagens is cultured with an auxiliary carbon source, methyl red and D-glucose at a low concentration below that which will trigger the production of D-glucose oxidase in the microorganism. Portions of the culture indicated by red are separated and increased. One such mutants has accession number NRRL 18927.
    Type: Grant
    Filed: September 17, 1997
    Date of Patent: February 2, 1999
    Assignee: The Board of Regents of the University of Nebraska
    Inventors: Fred W. Wagner, John P. Markwell
  • Patent number: 5432064
    Abstract: The present invention relates to the preparation of a novel heat-labile phosphatase enzyme from the filamentous fungus Aspergillus niger. This A. niger phosphatase enzyme has a native molecular weight of approximately 80,000 daltons, and is shown by polyacrylamide gel electrophoresis under denaturing conditions to be an alpha-2 dimer consisting of identical subunits of molecular weight of approximately 37,000 daltons each. The native intact enzyme molecule has an isoelectric point (pI) of 4.6, and exhibits optimal functional activity under reaction conditions of neutral to slightly alkaline pH conditions (about pH 7.0 to about pH 8.5). This enzyme has two characteristics which make it valuable in molecular biology laboratory protocols. First, the enzyme is readily inactivated by mild heating conditions (50.degree. C.); and second, the enzyme is highly specific for DNA as a substrate for the hydrolysis reaction; it does not hydrolyze adenosine triphosphate (ATP).
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: July 11, 1995
    Assignee: Board of Regents of the University of Nebraska
    Inventors: John P. Markwell, Wayne K. Versaw, John C. Osterman, Philip M. Kelley
  • Patent number: 5183752
    Abstract: The present invention relates to the preparation of a novel heat-labile phosphatase enzyme from the filamentous fungus Aspergillus niger. This A. Niger phosphatase enzyme has a native molecular weight of approximately 80,000 daltons, and is shown by polyacrylamide gel electrophoresis under denaturing conditions to be an alpha-2 dimer consisting of identical subunits of molecular weight of approximately 37,000 daltons each. The native intact enzyme molecule has an isoelectric point (pI) of 4.6, and exhibits optimal functional activity under reaction conditions of neutral to slightly alkaline pH conditions (about pH 7.0 to about pH 8.5). This enzyme has two characteristics which make it valuable in molecular biology laboratory protocols. First, the enzyme is readily inactivated by mild heating conditions (50.degree. C.); and second, the enzyme is highly specific for DNA as a substrate for the hydrolysis reaction; it does not hydrolyze adenosine triphosphate (ATP).
    Type: Grant
    Filed: October 29, 1990
    Date of Patent: February 2, 1993
    Assignee: Board of Regents of the University of Nebraska
    Inventors: John P. Markwell, Wayne K. Versaw, John C. Osterman, Philip M. Kelley