In one aspect, the present invention jointly expresses SOD and NAMPT proteins. The activity of SOD and NAMPT expressed by silkworm pupae inoculated with viruses is higher than that of silkworm pupae that are not inoculated with viruses, which proves that it is feasible to jointly express SOD and NAMPT with silkworms. It is expected to prepare an effective anti-aging drug.

The present disclosure provides an innovative method for improving the enzyme activity of an NMN biosynthetic enzyme Nampt, and relates to the technical field of genetic engineering. A mutant protein of the present disclosure is obtained by firstly analyzing a target protein Nampt using two softwares FoldX and DeepDDG, and then predicting multiple key sites influencing the enzyme functions and finally performing the semi-rational design of the enzyme. In the examples of the present disclosure, 10 mutant strains are constructed using the designed primers according to the principle of point mutation, and 8 of the mutants have higher activity than a wild-type strain, in which the NMN yield of the mutant Nampt-V365L is increased by 62%, and the NMN yields of the mutants Nampt-S248A, Nampt-N164L, Nampt-S382M, Nampt-A245T and Nampt-A208G are increased by 34%, 27%, 27%, 22% and 17% respectively.

The present invention addresses the problem of providing a method for producing nicotinamide mononucleotide, that produces nicotinamide mononucleotide using a single enzyme and using nucleoside monophosphate, pyrophosphate, and nicotinamide as starting materials. This problem is solved by a nicotinamide mononucleotide production method that includes at least the following steps 1) and 2): 1) a first step of producing phosphoribosyl diphosphate by the action of substantially one enzyme on nucleoside monophosphate and pyrophosphate; and 2) a second step of producing nicotinamide mononucleotide by the action of only substantially the aforementioned one enzyme on nicotinamide and the phosphoribosyl diphosphate that is the product of the first step.

The present invention relates to a method for producing synthetic extracellular vesicles comprising a lipid bilayer including at least two lipids, one or more extracellular vesicle associated proteins, and optionally one or more nucleic acid molecules. The inventive synthetic extracellular vesicles are formed by emulsification using a mechanic emulsifier in the form of polymer shell stabilized synthetic extracellular vesicles. The inventive method allows producing synthetic extracellular vesicles miming the composition and function of natural extracellular vesicles. Therefore, synthetic extracellular vesicles with specific protein and nucleic acids compositions are also disclosed herein, as well as their therapeutic uses.

Provided is a technique for synthesizing a nicotinamide derivative (NAm derivative) such as a nicotinamide mononucleotide (NMN) with high efficiency. A genetically modified microorganism is used, which can express, as nicotinamide phosphoribosylt ransferase (NAMPT), NAMPT having a conversion efficiency of 5-folds or more that of human NAMPT.

The present invention relates to various compositions comprising NAMPT and/or mutant thereof, processes for preparing these compositions, and various methods of using these compositions to prevent or treat an age-associated condition in a subject. The present invention also relates to methods of increasing NMN and/or NAD+ biosynthesis in a cell.

The invention discloses a genetically engineered bacterium in which the gene encoding adenine deaminase on the genome of the bacterium is knocked out or/and the gene encoding the enzyme in the NAD.sup.+ anabolic pathway is integrated on the genome of the bacterium. The invention also discloses a construction method of the above-mentioned genetically engineered bacteria. The gene encoding adenine deaminase on the genome of the host strain is knocked out to obtain a strain with high NAD.sup.+ yield. Or the expression cassettes of the gene encoding the enzyme in the NAD.sup.+ synthesis pathway are constructed separately, and then the enzyme encoding The gene expression cassette is integrated into the genome of the host strain whose gene encoding adenine deaminase is knocked out to construct a strain with high NAD.sup.+ production. The application of the above genetically engineered bacteria is disclosed. A method of producing NAD.sup.+ is disclosed.

The present disclosure is directed to methods (e.g., in vitro methods) for use of nicotinamide phosphoribosyltransferase (NAMPT) as a biomarker in radiation-induced lung injury (RILI). Provided herein is an in vitro method for the diagnosis, prognosis, and/or monitoring of RILI in a human subject by providing a tissue or plasma sample from the subject and detecting the level of NAMPT therein, wherein a higher level of NAMPT in the tissue or plasma sample from the subject compared to a healthy control or a reference value is indicative for the presence of RILI in the subject. Further provided herein is a method of detecting NAMPT in a human subject by obtaining a biological sample from the subject, detecting the presence of NAMPT in the sample by contacting the sample with a capture agent that specifically binds NAMPT, and detecting binding between NAMPT and the capture agent.

The present invention relates to a modified (mutant) nicotinamide phosphoribosyltransferase, and a method for producing nicotinamide mononucleotide using the same. The modified nicotinamide phosphoribosyltransferase (Nampt) of the present invention comprises the amino acid sequence represented by the following SEQ ID NO: 1 and/or the amino acid sequence represented by the following SEQ ID NO: 2, and has improved activity as compared with wild-type Nampt: (a) SEQ ID NO: 1: S- [V/I] -P-A-X.sub.1-X.sub.2-H-S-[T/V/I] - [M/V/I] -X.sub.3, and (b) SEQ ID NO: 2: X.sub.4-[S/I] -D-X.sub.5 wherein X.sub.1 to X.sub.5 are as defined herein.

The present disclosure provides an innovative method for improving the enzyme activity of an NMN biosynthetic enzyme Nampt, and relates to the technical field of genetic engineering. A mutant protein of the present disclosure is obtained by firstly analyzing a target protein Nampt using two softwares FoldX and DeepDDG, and then predicting multiple key sites influencing the enzyme functions and finally performing the semi-rational design of the enzyme. In the examples of the present disclosure, 10 mutant strains are constructed using the designed primers according to the principle of point mutation, and 8 of the mutants have higher activity than a wild-type strain, in which the NMN yield of the mutant Nampt-V365L is increased by 62%, and the NMN yields of the mutants Nampt-S248A, Nampt-N164L, Nampt-S382M, Nampt-A245T and Nampt-A208G are increased by 34%, 27%, 27%, 22% and 17% respectively.