Abstract: Provided are compositions and methods for used in solubilizing, stabilizing and expressing proteins. The proteins are fusion proteins that contain a protein of interest. The fusion proteins contain segments of Ribose Binding Protein (RBP) or Maltose Binding Protein (MBP). The fusion proteins can have the RBP or MBP segments flanking the target protein, and the RBP or MBP segments can be in the fusion protein in the same orientation as they normally occur (except for being interrupted by the target protein) or the segments can be permuted. Novel segments of the RBP and MBP are provided and result in improved expression and/or solubility of the proteins. Some examples include one or a combination of two complete or partial Histidine tags. Some examples allow for the target protein to be separated from all or a part of the fusion protein such as by enzymatic or non-enzymatic cleavage.

Abstract: Provided are compositions and methods for enhancing recombinant protein production. The compositions and methods involve use of Ribose Binding Protein (RBP) as a segment of a fusion polypeptide, whereby the RBP segment enhances production of the fusion protein. The fusion proteins contain the RBP sequentially in a single fusion protein with a polypeptide for which enhanced expression is desired. Recombinant expression vectors encoding the fusion proteins that contain and RBP segment are included, as are cells that contain the expression vectors. Methods for separating fusion proteins and for liberating a polypeptide segment that is part of the fusion protein are also provided.

Abstract: Provided are compositions and methods for used in solubilizing, stabilizing and expressing proteins. The proteins are fusion proteins that contain a protein of interest. The fusion proteins contain segments of Ribose Binding Protein (RBP) or Maltose Binding Protein (MBP). The fusion proteins can have the RBP or MBP segments flanking the target protein, and the RBP or MBP segments can be in the fusion protein in the same orientation as they normally occur (except for being interrupted by the target protein) or the segments can be permuted. Novel segments of the RBP and MBP are provided and result in improved expression and/or solubility of the proteins. Some examples include one or a combination of two complete or partial Histidine tags. Some examples allow for the target protein to be separated from all or a part of the fusion protein such as by enzymatic or non-enzymatic cleavage.

Abstract: Provided are compositions and methods for enhancing recombinant protein production. The compositions and methods involve use of Ribose Binding Protein (RBP) as a segment of a fusion polypeptide, whereby the RBP segment enhances production of the fusion protein. The fusion proteins contain the RBP sequentially in a single fusion protein with a polypeptide for which enhanced expression is desired. Recombinant expression vectors encoding the fusion proteins that contain and RBP segment are included, as are cells that contain the expression vectors. Methods for separating fusion proteins and for liberating a polypeptide segment that is part of the fusion protein are also provided.

Abstract: Provided are compositions and methods for enhancing recombinant protein production. The compositions and methods involve use of Ribose Binding Protein (RBP) as a segment of a fusion polypeptide, whereby the RBP segment enhances production of the fusion protein. The fusion proteins contain the RBP sequentially in a single fusion protein with a polypeptide for which enhanced expression is desired. Recombinant expression vectors encoding the fusion proteins that contain and RBP segment are included, as are cells that contain the expression vectors. Methods for separating fusion proteins and for liberating a polypeptide segment that is part of the fusion protein are also provided.

Abstract: Provided are compositions and methods for enhancing recombinant protein production. The compositions and methods involve use of Ribose Binding Protein (RBP) as a segment of a fusion polypeptide, whereby the RBP segment enhances production of the fusion protein. The fusion proteins contain the RBP sequentially in a single fusion protein with a polypeptide for which enhanced expression is desired. Recombinant expression vectors encoding the fusion proteins that contain and RBP segment are included, as are cells that contain the expression vectors. Methods for separating fusion proteins and for liberating a polypeptide segment that is part of the fusion protein are also provided.

Abstract: The present invention is a two-domain, bi-functional fusion protein that functions as a molecular switch wherein the free energy released by the folding of a first domain of the fusion protein drives an unfolding of a second domain of the fusion protein, and vice versa. The molecular structure of the fusion protein is engineered so that, at any time, the folding of the first domain necessarily unfolds the other domain, and vice versa, thereby making the folded and unfolded states of the first and second domains mutually exclusive. This is accomplished by the insertion of ubiquitin insert protein into a surface loop of barnase target protein subject to the structural design criterion that the N-C terminal length of the ubiquitin insert protein is at least two-times greater than the C?-C? alpha-carbon-alpha-carbon length of the surface loop of the barnase target protein.

Abstract: The invention is a fusion protein, embodying a mutually exclusive folding domain molecular switch, wherein the free energy released by folding of a first domain of the fusion protein drives an unfolding of a second domain of the fusion protein, and vice versa. The fusion protein is engineered so that folding the first domain unfolds the second domain, and vice versa, making the folded and unfolded states of the domains mutually exclusive. This is accomplished by insertion of an insert protein GCN4 into a surface loop of a target, protein barnase, subject to die topological design, criterion that the N—C terminal length of GCN4 be at least two-times greater than the C?-C? length of a surface loop of barnase. In the absence of the ligand AP-1, barnase is more stable and is folded and active. The presence of AP-1 induces folding of GCN4, forcibly unfolding and inactivating barnase.

Abstract: The present invention is a model for a mutually exclusive domain folding molecular switch comprising a two-domain, bifunctional fusion protein wherein the free energy released by the folding of a first domain of the fusion protein drives an unfolding of a second domain of the fusion protein, and vice versa. The molecular structure of the fusion protein is engineered so that, at any time, the folding of the first domain necessarily unfolds the other domain, and vice versa, thereby making the folded and unfolded states of the first and second domains mutually exclusive. This is accomplished by the insertion of an exemplary insert protein into a surface loop of an exemplary target protein subject to a novel structural design criterion wherein the N-C terminal length of the exemplary insert protein is at least two-times greater than the C&agr;-C&agr; length of the surface loop of the exemplary target protein.