MBP Antibody

Maltose-binding protein (MBP) is a well-characterized protein from Escherichia coli that plays a crucial role in the uptake and catabolism of maltodextrins. It is part of the maltose/maltodextrin system, which is a complex regulatory and transport system involving multiple proteins and protein complexes . MBP has been extensively studied for its structural, functional, and biotechnological applications.

MBP is a monomeric protein with an approximate molecular mass of 42.5 kilodaltons . It is encoded by the malE gene of E. coli, which produces a precursor polypeptide consisting of 396 amino acid residues. Upon cleavage of the NH2-terminal extension (26 residues), the mature MBP (370 residues) is formed . The protein is divided into two distinct globular domains connected by three short polypeptide segments. These domains are separated by a deep groove that contains the maltose/maltodextrin binding site .

The binding of maltose induces a significant conformational change in MBP, closing the groove by a rigid motion of the two domains around the linking polypeptide hinge . Both precursor and mature forms of MBP are functional for maltose binding, although the NH2-terminal extension decreases the folding rate of the precursor form relative to its mature form .

MBP is exported into the periplasmic space of E. coli . The NH2-terminal extension, also known as the signal peptide, has two primary roles: it slows down the folding of the newly synthesized polypeptide and directs it to the membrane and SecYEG translocon . Once folded, the precursor can no longer enter the translocation pathway . Mutations in the signal peptide can block export, highlighting its importance in the protein’s localization .

The malE gene, coding for MBP, is part of the Mal regulon of E. coli, which consists of ten genes involved in the efficient uptake and utilization of maltose and maltodextrins . These genes are clustered in the malB region of E. coli and organized into two divergent operons: malE-malF-malG and malK-lamB .

MBP is widely used as a fusion tag to enhance the solubility and expression of recombinant proteins in bacterial cells . Fusion of a target protein to MBP allows for a simple capture affinity step on amylose resin, resulting in a protein that is often 70-90% pure . Additionally, MBP fusion proteins exhibit increased protein production in mammalian cell lines and reduced cell death upon transient transfection . This makes MBP a versatile expression tag for protein production in various expression systems .

Mouse antibodies are immunoglobulins produced by mice in response to antigens. They are commonly used in research and therapeutic applications due to their specificity and effectiveness . However, the use of mouse antibodies in humans can lead to the development of human anti-mouse antibodies (HAMA), which can reduce the effectiveness of the treatment and cause allergic reactions . Despite these challenges, mouse antibodies remain valuable tools in preclinical studies and therapeutic research .