63 results about "Maltose-binding protein" patented technology

An intracellular selection system allows screening for peptide bioactivity and stability. Randomized recombinant peptides are screened for bioactivity in a tightly regulated expression system, preferably derived from the wild-type lac operon. Bioactive peptides thus identified are inherently protease- and peptidase-resistant. Also provided are bioactive peptides stabilized by a stabilizing group at the N-terminus, the C-terminus, or both. The stabilizing group can be a small stable protein, such as the Rop protein, glutathione sulfotransferase, thioredoxin, maltose binding protein, or glutathione reductase, an α-helical moiety, or one or more proline residues.

The invention discloses a preparation method of an aquaporin AqpZ. The method comprises the following steps: 1, amplifying Escherichia coli aquaporin AqpZ-HIS; 2, constructing a recombinant expression vector, carrying out construction and inducible expression of engineering strains, and carrying out ultrasonic fragmentation to obtain fusion protein MBP-AqpZ-HIS thalli; and 3, purifying to obtain the aquaporin AqpZ. The method realizes the efficient expression of a maltose-binding protein-aquaporin AqpZ-His-tag fusion protein in Escherichia coli, and overcomes problems comprising the toxicity of traditional AqpZ over-expression to host cells and insoluble inclusion body formation; and high-purity aquaporin AqpZ can be obtained only through two-time simple affinity chromatography separation of the aquaporin expressed through the method, so the method is simple to operate and is suitable for the industrialized production of the aquaporin AqpZ.

The invention provides a technical method for forming maltose binding protein-bacterial laccase fusion protein by fusing maltose binding protein and bacterial laccase and expressing the maltose binding protein-bacterial laccase fusion protein at low temperature. The method comprises the following steps: A, constructing a maltose binding protein-bacterial laccase gene; B, screening a positive converter; C, expressing fusion protein; D, identifying soluble fusion protein; E, purifying the fusion protein; and F, measuring parameters of enzyme kinetics of the bacterial laccase. The method realizes the high-level expression of the protein-bacterial laccase fusion protein in Escherichia coli cells. The soluble bacterial laccase can be expressed in high level and also maintains the same enzyme activity as unfused bacterial laccase. The problem that a large number of insoluble inclusion bodies are formed when the bacterial laccase is expressed in high level in the Escherichia coli cells is solved. The method has the advantages of simple operation, short fermentation time and low cost. The bacterial laccase also can be directly immobilized on maltose affinity chromatograph resin for various enzymatic reactions.

A strategy to improve protein stability by domain insertion. TEM 1 beta-lactamase (BLA) and exo-inulinase, as model target enzymes, are inserted into a hyperthermophilic maltose binding protein from Pyrococcus furiosus (PfMBP). Unlike conventional protein stabilization methods that employ mutations and recombinations, the inventive approach does not require any modification on a target protein except for its connection with a hyperthermophilic protein scaffold. For that reason, target protein substrate specificity was largely maintained, which is often modified through conventional protein stabilization methods. The insertion was achieved through gene fusion by recombinant DNA techniques.

The present invention refers to an enzyme consisting of a fusion protein particularly useful as shown through-out the present invention for carrying out the carbon-carbon bond-forming reaction known as the aldol Reaction, preferably for carrying out an aldol reaction by using aldehydes as substrates and preferably pyruvate or a salt thereof, for producing hydroxyketoacids. Said enzyme is made by binding an aldolase to a maltose binding protein. The enzymes display full activity under “highly denaturing” substrate loadings (aldehydes, >1 M).

The present invention provides a new method for recombinantly expressing a protein of interest, such as the human BRCA2 protein, BLM protein, CtIP protein, or EXOI protein, by expressing the protein in the form of a fusion protein comprising two maltose-binding protein (MBP) or glutathione-S-transferase (GST) tags. The expression cassette useful for this method and the fusion protein produced by this method are also described.