Patents by Inventor James R. Rasmussen

James R. Rasmussen 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).

  • Patent number: 5659015
    Abstract: This invention relates to a method of producing peracetyloxazolines from peracetyl saccharides. The method involves reacting the starting material, a peracetyl saccharide, with a reagent combination, to directly produce the peracetyl oxazoline. This method may be used for the activation of oligosaccharides, wherein an oligosaccharide containing a reducing GlcNAc terminus is activated by the formation of an oxazolide at the terminal GlcNAc, and then coupled with a bifunctional spacer to provide an oligosaccharide-spacer conjugate. The activated oligosaccharide-spacer conjugate is then coupled to a protein, such as granulocyte colony stimulating factor or .gamma.-interferon, providing a neoglycoprotein conjugate. The invention provides a method for forming neoglycoprotein conjugates which may improve biological and physiochemical properties of the protein. For example, serum lifetime or efficiency of drug delivery of the peptide to a target organ or cell may be improved.
    Type: Grant
    Filed: October 13, 1992
    Date of Patent: August 19, 1997
    Inventors: Marcelo Colon, Jeffrey T. Davis, James R. Rasmussen, Marianne Borowski, Barbara Y. Wan, Shirish Hirani
  • Patent number: 5324828
    Abstract: A derivatized 1-amino-1-deoxyoligosaccharide prepared by reacting, at a pH of at least 6.5, a glycopeptide or glycoprotein containing one or more Asn-linked oligosaccharides with a .beta.-aspartylglycosylamine amidohydrolase, and contacting the products with an electrophilic reagent.
    Type: Grant
    Filed: October 26, 1990
    Date of Patent: June 28, 1994
    Assignee: Genzyme Corporation
    Inventors: James R. Rasmussen, Jeffrey Davis
  • Patent number: 5283353
    Abstract: The invention resides in oligosaccharide derivatives which are obtained by the enzynmatic cleavage of carbohydrates linked to proteins through asparagine groups. The oligosaccharide moieties of the instant invention are 1-amino-1-deoxyoligosaccharide compounds which are cleaved from a glycoprotein with an aminohydrolase enzyme, wherein the amino group of the oligosaccharide is subsequently substituted with a fluorescent reporter compound. The compounds of the instant invention are characterized by the glycosylamine bonds exhibiting less than 10% hydrolysis at 25.degree. C. in aqueous solution over a two days at pH values between 4-10.
    Type: Grant
    Filed: June 5, 1990
    Date of Patent: February 1, 1994
    Assignees: Genzyme Corporation, Purdue Research Foundation
    Inventors: James R. Rasmussen, John M. Risley, Robert L. Van Etten
  • Patent number: 5272066
    Abstract: A method for modifying eukaryotic and prokaryotic proteins to extend their in vivo circulatory lifetimes. In the preferred embodiment, enzymatic and/or chemical treatments are used to produce a modified protein carrying one or more covalently attached trisaccharide, sialic acid.fwdarw.galactose.fwdarw.N-acetylglucosamine.fwdarw.(SA.fwdarw.Gal.fwd arw.GlcNAc.fwdarw.), or tetrasaccharide (SA.fwdarw.Gal.fwdarw.GlcNAc.fwdarw.GlcNAc.fwdarw.) moieties. The method can be applied to any natural or recombinant protein possessing asparagine-linked oligosaccharides or to any non-glycosylated protein that can be chemically or enzymatically derivatized with the appropriate carbohydrate units. Following injection into an animal, the modified glycoproteins are protected from premature clearance by cells of the liver and reticulo-endothelial system which recognize and rapidly internalize circulating glycoproteins with carbohydrate chains containing terminal Gal, GlcNAc, fucose or mannose residues.
    Type: Grant
    Filed: November 4, 1991
    Date of Patent: December 21, 1993
    Assignee: Massachusetts Institute of Technology
    Inventors: Michel L. E. Bergh, S. Catherine Hubbard, James R. Rasmussen
  • Patent number: 5241072
    Abstract: This invention relates to a method of producing peracetyloxazolines from peracetyl saccharides. The method involves reacting the starting material, a peracetyl saccharide, with a reagent combination, to directly produce the peracetyl oxazoline. This method may be used for the activation of oligosaccharides, wherein an oligosaccharide containing a reducing GlcNAc terminus is activated by the formation of an orazoline at the terminal GlcNAc, and then coupled with a bifunctional spacer to provide an oligosaccharide-spacer conjugate. The activated oligosaccharide-spacer conjugate is then coupled to a protein, such as granulocyte colony stimulating factor or .gamma.-interferon, providing a neoglycoprotein conjugate. The invention provides a method for forming neoglycoprotein conjugates which may improve biological and physiochemical properties of the protein. For example, serum lifetime or efficiency of drug delivery of the peptide to a target organ or cell may be improved.
    Type: Grant
    Filed: May 25, 1990
    Date of Patent: August 31, 1993
    Assignee: Genzyne Corporation
    Inventors: Marcelo Colon, Jeffrey T. Davis, James R. Rasmussen, Marianne Borowski, Barbara Y. Wan, Shirish Hirani
  • Patent number: 5238821
    Abstract: An enzyme sample having Peptide-N.sup.4 -(N-acetyl-.beta.-N-glucosaminyl) asparagine Aminidase F (PNGase F) activity completely free from Endo-.beta.-N-acetylglucosaminidase F (Endo F) activity.
    Type: Grant
    Filed: November 20, 1991
    Date of Patent: August 24, 1993
    Assignee: Genzyme Corporation
    Inventors: Gary D. Barsomian, James R. Rasmussen, Tracy L. Johnnson
  • Patent number: 4925796
    Abstract: A method for modifying eukaryotic and prokaryotic proteins to extend their in vivo circulatory lifetimes. In the preferred embodiment, enzymatic and/or chemical treatments are used to produce a modified protein carrying one or more covalently attached trisaccharide, sialic acid.fwdarw.galactose.fwdarw.N-acetylglucosamine.fwdarw.(SA.fwdarw.Gal.fwd arw.GlcNac.fwdarw.), or tetrasaccharide (SA.fwdarw.Gal.fwdarw.GlcNAc.fwdarw.GlcNAc.fwdarw.) moieties. The method can be applied to any natural or recombinant protein possessing asparagine-linked oligosaccharides or to any non-glycosylated protein that can be chemically or enzymatically derivatized with the appropriate carbohydrate units. Following injection into an animal, the modified glycoproteins are protected from premature clearance by cells of the liver and reticulo-endothelial system which recognize and rapidly internalize circulating glycoproteins with carbohydrate chains containing terminal Gal, GlnNAc, fucose or mannose residues.
    Type: Grant
    Filed: March 7, 1986
    Date of Patent: May 15, 1990
    Assignee: Massachusetts Institute of Technology
    Inventors: Michel L. E. Bergh, S. Catherine Hubbard, James R. Rasmussen
  • Patent number: 4895776
    Abstract: An improved high temperature electrochemical cell employing a molten alkali metal anolyte, a solid ceramic electrolyte containing mobile alkali metal ions, and a molten sulfur/selenium catholyte is disclosed.
    Type: Grant
    Filed: October 26, 1988
    Date of Patent: January 23, 1990
    Assignee: Ceramatec, Inc.
    Inventors: Anil V. Virkar, Gerald R. Miller, James R. Rasmussen
  • Patent number: 4496639
    Abstract: A method for lowering the activation energy of a polycrystalline ceramic electrolyte is disclosed. Polycrystalline ceramic electrolytes, such as beta-alumina, when contacted with hydrogen selenide exhibit a lower activation energy than untreated electrolytes.
    Type: Grant
    Filed: July 5, 1983
    Date of Patent: January 29, 1985
    Assignee: Ceramatec, Inc.
    Inventors: James R. Rasmussen, Anil V. Virkar