Abstract:
The present invention relates to the C3b/C4b receptor (CR1) gene and its encoded protein. The invention also relates to CR1 nucleic acid sequences and fragments thereof comprising 70 nucleotides and their encoded peptides or proteins comprising 24 amino acids. The invention further provides for the expression of the CR1 protein and fragments thereof. The genes and proteins of the invention have uses in diagnosis and therapy of disorders involving complement activity, and various immune system or inflammatory disorders. In specific embodiments of the present invention detailed in the examples sections infra, the cloning, nucleotide sequence, and deduced amino acid sequence of a full-length CR1 cDNA and fragments thereof are described. The expression of the CR1 protein and fragments thereof is also described. Also described is the expression of a secreted CR1 molecule lacking a transmembrane region. The secreted CR1 molecule is shown to be useful in reducing damage caused by inflammation and in reducing myocardial infarct size and preventing reperfusion injury.
Abstract:
Embodiments of the invention relate to vector constructs and methods for expression of polypeptides including multimeric products such as therapeutic antibodies. Particular constructs allow for the generation of expression products from a single open reading frame (sORF). An embodiment provides an isolated or purified expression vector for generating one or more recombinant protein products comprising a single open reading frame insert; said insert comprising a signal peptide nucleic acid sequence encoding a signal peptide; a first nucleic acid sequence encoding a first polypeptide; a first intervening nucleic acid sequence encoding a first protein cleavage site, wherein said first protein cleavage site is provided by an intein segment of a Ion protease gene of Pyrococcus or a klbA gene of Pyrococcus or Methanococcus , or a modified intein segment derived therefrom; and a second nucleic acid sequence encoding a second polypeptide. Certain embodiments of constructs and methods employ an intein segment of a Ion protease gene of Pyrococcus abyssi , Pyrococcus furiosus , or Pyrococcus horikoshii OT3; or an intein segment of a klbA gene of Pyrococcus abyssi , Pyrococcus furiosus , or Methanococcus jannaschii ; or other intein segment.
Abstract:
Compositions and methods comprising recombinant expression vector elements (rEVEs) to enhance the level of expression of recombinant proteins are described. Other compositions and methods for lowering, substantially suppressing, or essentially silencing expression of a recombinant protein are also described.
Abstract:
Disclosed are useful constructs and methods for the expression of proteins using primary translation products that are processed within a recombinant host cell. Constructs comprising a single open reading frame (sORF) are described for protein expression including expression of multiple polypeptides. A primary translation product (a pro-protein or a polyprotein) contains polypeptides such as inteins or hedgehog family auto-processing domains, or variants thereof, inserted in frame between multiple protein subunits of interest. The primary product can also contain cleavage sequences such as other proteolytic cleavage or protease recognition sites, or signal peptides which contain recognition sequences for signal peptidases, separating at least two of the multiple protein subunits. The sequences of the inserted auto-processing polypeptides or cleavage sites can be manipulated to enhance the efficiency of expression of the separate multiple protein subunits. Also disclosed are independent aspects of conducting efficient expression, secretion, and/or multimeric assembly of proteins such as immunoglobulins. Where the polyprotein contains immunoglobulin heavy and light chain segments or fragments capable of antigen recognition, in an embodiment a selectable stoichiometric ratio is at least two copies of a light chain segment per heavy chain segment, with the result that the production of properly folded and assembled functional antibody is made. Modified signal peptides, including such from immunoglobulin light chains, are described.
Abstract:
Disclosed are useful constructs and methods for the expression of proteins using primary translation products that are processed within a recombinant host cell. Constructs comprising a single open reading frame (sORF) are described for protein expression including expression of multiple polypeptides. A primary translation product (a pro-protein or a polyprotein) contains polypeptides such as inteins or hedgehog family auto-processing domains, or variants thereof, inserted in frame between multiple protein subunits of interest. The primary product can also contain cleavage sequences such as other proteolytic cleavage or protease recognition sites, or signal peptides which contain recognition sequences for signal peptidases, separating at least two of the multiple protein subunits. The sequences of the inserted auto-processing polypeptides or cleavage sites can be manipulated to enhance the efficiency of expression of the separate multiple protein subunits. Also disclosed are independent aspects of conducting efficient expression, secretion, and/or multimeric assembly of proteins such as immunoglobulins. Where the polyprotein contains immunoglobulin heavy and light chain segments or fragments capable of antigen recognition, in an embodiment a selectable stoichiometric ratio is at least two copies of a light chain segment per heavy chain segment, with the result that the production of properly folded and assembled functional antibody is made. Modified signal peptides, including such from immunoglobulin light chains, are described.
Abstract:
The invention features a method for monitoring the stability of a protein or other cellular product secreted by cells in a fermenter culture. The method involves, harvesting from a fermenter culture a first sample of cells that secrete a protein or cellular product and incorporating the cells from the first sample into gel microdrops (GMDs), and measuring secretion of the protein or cellular product by cells in one or more GMD samples over time. The protein secreted by the cells may be, for example, an antibody, cytokine, or growth factor. The cellular product secreted by the cells may be, for example, an antibiotic, amino acid, vitamin, or carbohydrate.
Abstract:
Compositions and methods comprising recombinant expression vector elements (rEVEs) to enhance the level of expression of recombinant proteins are described. Other compositions and methods for lowering, substantially suppressing, or essentially silencing expression of a recombinant protein are also described.