Method for Cloning Secreted Proteins
Summary Many biologically important molecules, including many used therapeutically, are secreted proteins, such as interferons, erythropoietin and insulin. Secreted proteins have a hydrophobic signal peptide at the amino terminus of the protein. This hydrophobic signal sequence is typically about 16 to 30 amino acids long and contains one or more positively charged amino acid residues near its N-terminus, followed by a continuous stretch of hydrophobic residues. This signal peptide is recognized by a signal recognition particle (SRP) which in turn interacts with a SRP receptor, located on the endoplasmic reticulumn (ER). At some point during or after protein synthesis, the protein is translocated across the ER membrane into the ER lumen, where the signal peptide is cleaved off, and the protein secreted.Most systems recently developed to isolate nucleic acids encoding secreted protein are based on sequence signal traps (example: Genetic Institute's DiscoverEase tm). These systems have several drawbacks. They are based on the construction of in frame hybrid fusion proteins, limiting the percentage of usable clones. They depend on the secretion of the protein, preventing researchers from cloning proteins that have a signal peptide that are trapped in the ER.
Harvard Medical School researchers have developed a system that does not have the limitations of sequence signal traps, and enable more efficient ad reliable identification of secreted proteins. This method allows researchers to efficiently generate cDNAs coding for secreted proteins whether or not the protein is actually secreted. It is only necessary to have the signal peptide.
Advantages:
Not dependent on secretion of target:
This approach allows researchers to generate cDNAs for proteins that may not be identified by other approaches dependent on the actual extracellular secretion of the protein.
US Patent 6,066,460 issued 5/23/00 for this technology.
Applications Isolation of secreted proteins: Secreted proteins are by far the most common class of peptides in therapeutic use. For Further Information Please Contact the Director of Business Development Michal Preminger Email: [email protected] Telephone: (617) 432-0920
Inventor(s): Kirschner, Marc W.
Type of Offer: Licensing
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