Maltose binding protein
Encyclopedia
Maltose-Binding Protein is a part of the maltose
/maltodextrin
system of Escherichia coli
, which is responsible for the uptake and efficient catabolism
of maltodextrins. It is a complex regulatory and transport system involving many protein
s and protein complexes. MBP has an approximate molecular mass of 42.5 kilodaltons.
, preventing aggregation of the protein of interest. The mechanism by which MBP increases solubility is not well understood. In addition, MBP can itself be used as an affinity tag for purification
of recombinant proteins. The fusion protein binds to amylose
columns while all other proteins flow through. The MBP-protein fusion can be purified by eluting the column with maltose. Once the fusion protein is obtained in purified form, the protein of interest (X) is often cleaved from MBP with a specific protease
. Protein X can then be separated from MBP by ion exchange chromatography.
Maltose
Maltose , or malt sugar, is a disaccharide formed from two units of glucose joined with an αbond, formed from a condensation reaction. The isomer "isomaltose" has two glucose molecules linked through an α bond. Maltose is the second member of an important biochemical series of glucose chains....
/maltodextrin
Maltodextrin
Maltodextrin is a polysaccharide that is used as a food additive. It is produced from starch by partial hydrolysis and is usually found as a creamy-white hygroscopic spraydried powder. Maltodextrin is easily digestible, being absorbed as rapidly as glucose, and might be either moderately sweet or...
system of Escherichia coli
Escherichia coli
Escherichia coli is a Gram-negative, rod-shaped bacterium that is commonly found in the lower intestine of warm-blooded organisms . Most E. coli strains are harmless, but some serotypes can cause serious food poisoning in humans, and are occasionally responsible for product recalls...
, which is responsible for the uptake and efficient catabolism
Catabolism
Catabolism is the set of metabolic pathways that break down molecules into smaller units and release energy. In catabolism, large molecules such as polysaccharides, lipids, nucleic acids and proteins are broken down into smaller units such as monosaccharides, fatty acids, nucleotides, and amino...
of maltodextrins. It is a complex regulatory and transport system involving many protein
Protein
Proteins are biochemical compounds consisting of one or more polypeptides typically folded into a globular or fibrous form, facilitating a biological function. A polypeptide is a single linear polymer chain of amino acids bonded together by peptide bonds between the carboxyl and amino groups of...
s and protein complexes. MBP has an approximate molecular mass of 42.5 kilodaltons.
Use
MBP is used to increase the solubility of recombinant proteins expressed in E. coli. In these systems, the protein of interest is often expressed as a MBP-fusion proteinFusion protein
Fusion proteins or chimeric proteins are proteins created through the joining of two or more genes which originally coded for separate proteins. Translation of this fusion gene results in a single polypeptide with functional properties derived from each of the original proteins...
, preventing aggregation of the protein of interest. The mechanism by which MBP increases solubility is not well understood. In addition, MBP can itself be used as an affinity tag for purification
Purification
Purification is the process of rendering something pure, i.e. clean of foreign elements and/or pollution, and may refer to:* List of purification methods in chemistry* Water purification** Organisms used in water purification...
of recombinant proteins. The fusion protein binds to amylose
Amylose
Amylose is a linear polymer made up of D-glucose units.This polysaccharide is one of the two components of starch, making up approximately 2-30% of the structure...
columns while all other proteins flow through. The MBP-protein fusion can be purified by eluting the column with maltose. Once the fusion protein is obtained in purified form, the protein of interest (X) is often cleaved from MBP with a specific protease
Protease
A protease is any enzyme that conducts proteolysis, that is, begins protein catabolism by hydrolysis of the peptide bonds that link amino acids together in the polypeptide chain forming the protein....
. Protein X can then be separated from MBP by ion exchange chromatography.
External links
- N-Terminal Fusion of Target Protein to Maltose-Binding Protein at Michigan Technological UniversityMichigan Technological UniversityMichigan Technological University is a public research university located in Houghton, Michigan, United States. Its main campus sits on on a bluff overlooking Portage Lake...
- Generic protocol for the expression and purification of recombinant proteins in Escherichia coli using a combinatorial His6-maltose binding protein fusion tag