Patents by Inventor Alan W. Hammond

Alan W. Hammond 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).

  • Cloned KpnI restriction-modification system
    Patent number: 5192675
    Abstract: The present invention discloses the cloning and expression in a host such as Escherichia coli of the KpnI restriction-modification system from Klebsiella pneumoniae, utilizing a two step protocol. Initial protection of the E. coli host with methylase expressed on a vector was required to stabilize a compatible vector carrying both the endonuclease and the methylase genes on a single DNA fragment. A chromosomal map was generated localizing the genes for KpnI methylase and endonuclease. An E. coli strain was constructed which produced several thousand-fold higher levels of KpnI endonuclease than the level produced by Klebsiella pneumoniae. This invention is also directed to cloning and expression of genes encoding for restriction endonuclease isoschizomers of KpnI and/or modification methylase isoschizomers of KpnI methylase.
    Type: Grant
    Filed: January 17, 1992
    Date of Patent: March 9, 1993
    Assignee: Life Technologies, Inc.
    Inventors: Deb K. Chatterjee, Alan W. Hammond
  • Host expressing NgoAIII restriction endonuclease and modification methylase from neisseria
    Patent number: 5147800
    Abstract: The present invention is directed to recombinant hosts which contain and express various Type II restriction endonuclease and/or modification methylase genes. In particular, the present invention is concerned with the cloned restriction endonucleases, NgoAIII and NgoAI, which recognize and cleave within or near the double-stranded DNA sequence, 5' CCGCGG 3' and 5' PuGCGCPy 3', respectively. Also provided in this invention are cloned modification methylase genes corresponding to said restriction endonucleases. This invention is further concerned with a cloned modification methylase, M.NgoAII. One source of these enzymes is Neisseria gonorrhoeae, although other microorganisms may be used to isolate the restriction endonuclease isoschizomers and modification methylase isoschizomers of this invention.
    Type: Grant
    Filed: June 8, 1990
    Date of Patent: September 15, 1992
    Assignee: Life Technologies, Inc.
    Inventors: Alan W. Hammond, Deb K. Chatterjee
  • Cloned KpnI restriction-modification system
    Patent number: 5082784
    Abstract: The present invention discloses the cloning and expression in a host such as Escherichia coli of the KpnI restriction-modification system from Klebsiella pneumoniae, utilizing a two step protocol. Initial protection of the E. coli host with methylase expressed on a vector was required to stabilize a compatible vector carrying both the endonuclease and the methylase genes on a single DNA fragment. A chromosomal map was generated localizing the genes for KpnI methylase and endonuclease. An E. coli strain was constructed which produced several thousand-fold higher levels of KpnI endonuclease than the level produced by Klebsiella pneumoniae. This invention is also directed to cloning and expression of genes encoding for restriction endonuclease isoschizomers of KpnI and/or modification methylase isoschizomers of KpnI methylase.
    Type: Grant
    Filed: March 20, 1990
    Date of Patent: January 21, 1992
    Assignee: Life Technologies, Inc.
    Inventors: Deb K. Chatterjee, Alan W. Hammond