The present disclosure relates to a method for constructing a trehalose polyenzyme complex in vitro by mediation of an artificial scaffold protein, which mainly comprises the following steps: constructing a recombinant bacterium WB800n-ScafCCR for self-assembled scaffold protein module; constructing a recombinant bacterium WB800n-P43-phoD-treY-Ccdoc for self-assembled catalytic module; constructing a recombinant bacterium WB800n-P43-phoD-treZ-Ctdoc for self-assembled catalytic module; constructing a recombinant bacterium WB800n-P43-phoD-cgt-Rfdoc for self-assembled catalytic module; secretorily expressing the recombinant bacteria and self-assembling in vitro to obtain a recombinant trehalose multi-enzyme complex. The trehalose multi-enzyme complex constructed by the method of the present disclosure has a higher catalytic efficiency in preparing trehalose than that of mixed free enzymes, and the method can be used for production of high quality trehalose after immobilization with cellulose microspheres.

The present disclosure discloses a maltooligosyl trehalose synthase mutant with improved thermal stability, and belongs to the technical fields of enzyme engineering and protein engineering. The residual enzyme activities of the MTSase mutants S361R, S444E, S361R/S444E, S361K/S444E, G415P/S361R/S444E and G415P consistent with the present disclosure after treatment at 60 C. for 10 min are respectively 70.3%, 50.1%, 83.5%, 65.9%, 100% and 80.7%, which are respectively 1.6, 1.1, 1.9, 1.5, 2.3 and 1.9 times of that of the wild type. The half-lives of the S361R/S444E and G415P/S361R/S444E at 60 C. are respectively 14.9 min and 90.8 min which are respectively 3.2 and 19.7 times of that of the wild type, indicating that the thermal stability of the MTSase mutant consistent with the present disclosure is significantly improved than that of the wild type.

The present disclosure discloses a maltooligosyl trehalose synthase mutant with improved thermal stability, and belongs to the technical fields of enzyme engineering and protein engineering. The residual enzyme activities of the MTSase mutants S361R, S444E, S361R/S444E, S361K/S444E, G415P/S361R/S444E and G415P consistent with the present disclosure after treatment at 60 C. for 10 min are respectively 70.3%, 50.1%, 83.5%, 65.9%, 100% and 80.7%, which are respectively 1.6, 1.1, 1.9, 1.5, 2.3 and 1.9 times of that of the wild type. The half-lives of the S361R/S444E and G415P/S361R/S444E at 60 C. are respectively 14.9 min and 90.8 min which are respectively 3.2 and 19.7 times of that of the wild type, indicating that the thermal stability of the MTSase mutant consistent with the present disclosure is significantly improved than that of the wild type.

The present invention relates to the field of genetic engineering and enzyme engineering, and more particularly relates to a maltooligosyl trehalose synthase mutant and its application. The present invention provides a series of maltooligosyl trehalose synthase mutants with improved enzyme activity.

The present disclosure relates to a method for constructing a trehalose polyenzyme complex in vitro by mediation of an artificial scaffold protein, which mainly comprises the following steps: constructing a recombinant bacterium WB800n-ScafCCR for self-assembled scaffold protein module; constructing a recombinant bacterium WB800n-P43-phoD -treY-Ccdoc for self-assembled catalytic module; constructing a recombinant bacterium WB800n-P43-phoD-treZ-Ctdoc for self-assembled catalytic module; constructing a recombinant bacterium WB800n-P43-phoD-cgt-Rfdoc for self-assembled catalytic module; secretorily expressing the recombinant bacteria and self-assembling in vitro to obtain a recombinant trehalose multi-enzyme complex. The trehalose multi-enzyme complex constructed by the method of the present disclosure has a higher catalytic efficiency in preparing trehalose than that of mixed free enzymes, and the method can be used for production of high quality trehalose after immobilization with cellulose microspheres.

The present invention relates to the field of genetic engineering and enzyme engineering, and more particularly relates to a maltooligosyl trehalose synthase mutant and its application.The present invention provides a series of maltooligosyl trehalose synthase mutants with improved enzyme activity.

The present invention relates to the field of genetic engineering and enzyme engineering, and more particularly relates to a maltooligosyl trehalose synthase mutant and its application. The present invention provides a series of maltooligosyl trehalose synthase mutants with improved enzyme activity.