# Patent

## Title
Composition for astringin product

## Abstract

Provided is a composition for producing astringin among metabolites of polydatin, wherein the astringin may be mass-produced by oxidizing the polydatin using a CYP102A1 chimera and mutants thereof as a catalyst, the CYP102A1 chimera being produced by fusing a reductase domain of a wild-type CYP102A1 which is a bacterial cytochrome P450 enzyme, with a heme domain of a CYP102A1 mutant.

## Background
CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority under 35 U.S.C. § 119 to Korean Patent Application No. 10-2015-0128399, filed on Sep. 10, 2015, in the Korean Intellectual Property Office, the disclosure of which is incorporated herein by reference in its entirety.
INCORPORATION BY REFERENCE OF ELECTRONICALLY SUBMITTED MATERIAL
Incorporated by reference in its entirety herein is a computer-readable nucleotide and amino acid sequence listing submitted herewith and identified as follows: 28,120 bytes ASCII (Text) file named “Substitute_Sequence_Listing_PLS16309,” created Sep. 9, 2016.
TECHNICAL FIELD
The following disclosure relates to a novel composition including a bacterial cytochrome P450 chimera for producing astringin or mutants thereof, a kit and a method for producing astringin using the same.
BACKGROUND
Polydatin which is known as stilbenoid-based drug has effects on anti-oxidant, anti-aging, anti-virus, neuroprotective action, and anti-inflammatory action. Polydatin is a stilbenoid glucoside, and is a derivative of resveratrol, and the stilbenoid-based drug such as polydatin is known to be metabolized by CYP1A2 and CYP1B1 which are cytochrome P450 enzymes present in human liver. However, metabolic pathways and metabolites of polydatin have not been specifically known so far.
The cytochrome P450 enzyme is present throughout all living organisms including archaea, bacteria, fungi, plants, animals, and human, and corresponds to a large family consisting of enzymes serving as catalysts promoting various oxidation reaction (http://drnelson.uthsc.edu/CytochromeP450.html).
P450 is significantly various in view of kinds, and may function as catalysts for a wide range of substrates, thereby having a potential for being effectively useful as a biological catalyst in production of fine chemicals such as pharmaceutical products. However, despite the potential usefulness, P450 enzymes have problems in being used as a biological catalyst due to low stability, catalytic activity, and availability.
P450 is capable of being used to synthesize drug metabolites, in particular, chiral metabolites by a simple, highly efficient, and environment-friendly method, wherein the synthesis of the chiral metabolites is not suitably performed by chemical methods, but needs to use an enzyme. If the drug acts as a prodrug, the drug is converted to a biologically active metabolite by P450s of the human liver when the drug metabolizes after administration. Here, in order to conduct research into drug efficacy, toxic, pharmacokinetics, and the like, of active metabolites produced from the prodrugs, a large amount of pure metabolites are needed. Further, when the metabolites themselves have biological activities, direct administration of the metabolites in vivo may provide big benefits, such that technique for mass-producing the metabolites is significantly important.
However, there are a lot of problems in chemically synthesizing pure metabolites. In addition, as an alternative thereof, a human P450 enzyme is used, but it is technically almost impossible to directly separate only P450 enzymes from a human sample. Further, even in the case of animal-derived P450, it is difficult to perform pure-separation, and enzyme activity is also low. In order to solve the problems, there was an attempt to produce metabolites using human P450 which is heterologously expressed in E. coli or insect cells, but the attempt has problems such as limited stability, a slow response rate, high cost and low productivity.
As another method, there was a method using bacterial P450 enzymes which are engineered to have catalytic activity, and a possibility that P450 enzymes capable of functioning on various substrates are appropriately usable for producing biotechnological metabolites by using the engineered enzymes has been reported.
Therefore, the present inventors conducted research into pathways and metabolites of polydatin, found bacterial P450 chimera enzyme capable of selectively producing specific metabolites among the metabolites of polydatin, and completed the present invention.
RELATED ART DOCUMENT
(Patent Document 1) Korean Patent No. 1348984
SUMMARY
An embodiment of the present invention is directed to providing a novel composition including a bacteria P450 chimeric enzyme capable of mass-producing astringin among metabolites of polydatin that is not capable of being mass-produced by chemical synthesis, and mutants thereof.
In one general aspect, there is provided a composition for producing astringin including at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, and producing astringin by oxidizing polydatin, wherein the CYP102A1 chimera is R47L/F81I/F87V/E143G/L188Q/E267V/A475V/E559D/T665A/P676L/A679E/E688A/A742G/K814E/R826S/R837H/E871N/1882V/E888G/P895S/S955N/M968V/Q982R/A1009D/H1022Y/Q1023E of a CYP102A1 mutant, the CYP102A1 mutant is R47L/F81I/F87V/E143G/L188Q/E267V of a wild-type CYP102A1, and the mutant of CYP102A1 chimera is at least one selected from the group consisting of F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/E267V, R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/E267V, and R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T of the CYP102A1 chimera.
In another general aspect, there is provided a method for producing astringin including: reacting at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, using polydatin as a substrate, wherein the CYP102A1 chimera is R47L/F81I/F87V/E143G/L188Q/E267V/A475V/E559D/T665A/P676L/A679E/E688A/A742G/K814E/R826S/R837H/E871N11882V/E888G/P895S/S955N/M968V/Q982R/A1009D/H1022Y/Q1023E of a CYP102A1 mutant, the CYP102A1 mutant is R47L/F81I/F87V/E143G/L188Q/E267V of a wild-type CYP102A1, and the mutant of CYP102A1 chimera is at least one selected from the group consisting of F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/E267V, R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/E267V, and R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T of the CYP102A1 chimera.



BRIEF DESCRIPTION OF THE DRAWINGS
In FIG. 1, (A) shows comparison between peak of a new metabolite with NADPH-generating system and peak of a metabolite without the NADPH-generating system, and (B) shows astringin which is a 3′-OH hydroxylated product by mutants of CYP102A1 chimera.
In FIG. 2, (A) shows LC-MS elution profiles of polydatin metabolites produced by the mutant 387 of bacteria CYP102A1 chimera, wherein peaks were shown at 5.182 min (3-hydroxypolydatin) and 6.453 min (polydatin) in the mass spectra. Further, the 3′-hydroxylated product and polydatin produced by mutant 387 of CYP102A1 chimera were observed at 391 (B) and 407 (C) ([M+H]+) in mass spectra, respectively.
FIG. 3 shows analysis results of kinetic parameter by comparing production efficiency of 3′-hydroxylated products by bacteria CYP102A1 chimera (M16V3) and mutants (306, 380, 387) of CYP102A1 chimera.
FIG. 4 shows results of the obtained products by NMR analysis, confirming that the obtained products are astringin (A) which is 3′-hydroylated product and polydatin (B).
FIG. 5 shows production of astringin by oxidation of polydatin.
FIG. 6 shows amino acid sequence of wild-type bacteria CYP102A1, and numbering of the amino acid sequences starts from threonine (T) which is a second amino acid, rather than methionine (M).
FIG. 7 shows base sequence of CYP102A1 chimera (M16V3), SEQ ID NO: 17.
FIG. 8 shows amino acid sequence of CYP102A1 chimera (M16V3), SEQ ID NO:
FIG. 9 shows base sequence of a mutant #16 of a wild-type CYP102A1 SEQ ID NO: 19.



DETAILED DESCRIPTION OF EMBODIMENTS
Hereinafter, the present invention is described in detail. Unless indicated otherwise in the specification, it is to be understood that all the technical terms used in the specification are construed as meaning as those that are generally understood by those skilled in the art. Further, in the drawings for describing the present invention, portions will be omitted so as not to obscure the gist of the present invention, and may be exaggerated in the range in which the gist of the present invention is not obscured.
The present invention provides a novel composition including a bacterial cytochrome P450 chimera enzyme capable of producing astringin which is 3′-hydroxypolydatin among metabolites of polydatin, and mutants thereof.
The present invention provides a method for producing astringin from polydatin by using wild-type CYP102A1 which is bacterial cytochrome P450 BM3 as a bacterial cytochrome P450 chimeric enzyme, a CYP102A1 chimera fused from a mutant thereof or a mutant of CYP102A1 chimera as a catalyst, a composition thereof, and a kit including the same.
In the present invention, the chimera may include at least two different binding domains. The two binding domains may be derived from different wild-type proteins or mutants, and the two binding domains may be derived from the same wild-type proteins or mutants.
The present invention provides a composition for producing astringin including at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, and producing astringin by oxidizing polydatin, wherein the CYP102A1 chimera is R47L/F81I/F87V/E143G/L188Q/E267V/A475V/E559D/T665A/P676L/A679E/E688A/A742G/K814E/R826S/R837H/E871N11882V/E888G/P895S/S955N/M968V/Q982R/A1009D/H1022Y/Q1023E of a CYP102A1 mutant, the CYP102A1 mutant is R47L/F81I/F87V/E143G/L188Q/E267V of a wild-type CYP102A1, and the mutant of CYP102A1 chimera is at least one selected from the group consisting of F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/E267V, R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/E267V, and R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T of the CYP102A1 chimera.
In the present invention, the CYP102A1 chimera may be produced by fusing a heme domain of wild-type CYP102A1 mutant with a reductase domain of a natural variant of the wild-type CYP102A1, and may be positioned with a different arrangement from proteins of the wild-type CYP102A1 mutants.
The natural variants in the present invention mean mutants which are confirmed to be present in nature by analyzing base sequence of CYP102A1 gene of bacillus sp. that is collected in the nature and deposited, in addition to CYP102A1 which is previously known in the art.
In the present invention, the CYP102A1 chimera was selected from mutants having a large catalytic activity to substrates among the mutants obtained by mass-expressing the wild-type CYP102A1 and site-directed mutants thereof in E. coli, and may be produced by fusing the heme domain of the selected CYP102A1 mutant with the reductase domain of the natural variant of the wild-type CYP102A1. Further, the mutant of CYP102A1 chimera may be selected from mutants having a large catalytic activity by mass-expressing the site-directed mutants of the produced chimera in E. coli. 
In the present invention, the CYP102A1 mutants have sequences changed by natural or artificial substitution, deletion, addition and/or insertion in wild-type CYP102A1 protein amino acids. Preferably, the amino acids to be substituted may be substituted to have similar characteristics to amino acids that will be substituted. For example, alanine, valine, leucine, isoleucine, proline, methionine, phenylalanine and tryptophan are classified into non-polar amino acids, and may have similar characteristics to be substituted with each other. Amino acids having no charges include glycine, serine, threonine, cysteine, tyrosine, asparagine, and glutamine, which may be substituted with each other. Further, acidic amino acids include aspartic acid and glutamic acid, which may be substituted with each other, and basic amino acids include lysine, arginine, and histidine, which may be substituted with each other.
The CYP102A1 mutants may be produced by mutagenesis methods known in the art. For example, a deletion-mutagenesis method (Kowalski D et al., J. BioChem., 15, 4457 reference), PCT method, Kunkel method, a site-directed mutagenesis method, DNA shuffling, a staggered extension process (StEP), an error-prone PCR method may be used.
In the present invention, the CYP102A1 mutant may include polypeptide including amino acid sequences having at least 50%, preferably 70%, more preferably 90% identity to the wild-type CYP102A1 amino acid sequence consisting of SEQ ID NO: 16.
According to an exemplary embodiment of the present invention, the CYP102A 1 mutant may include at least one substitution selected from the group consisting of an arginine (R) (47th amino acid of the wild-type CYP102A1) to leucine (L) substitution, a phenylalanine (F) (81th amino acid of the wild-type CYP102A1) to isoleucine (I) substitution, a phenylalanine (F) (87th amino acid of the wild-type CYP102A1) to valine (V) substitution, a glutamic acid (E) (143th amino acid) to glycine (G) substitution, a leucine (L) (188th amino acid) to glutamine (Q) substitution, and a glutamic acid (E) (267th amino acid) to valine (V) substitution.
In the present invention, the preferable CYP102A1 mutant may be R47L/F81I/F87V/E143G/L188Q/E267V of the wild-type CYP102A1, but the present invention is not limited thereto.
In the present invention, the CYP102A1 mutant may be represented by an amino acid prior to the mutation, a position of the amino acid in SEQ ID NO: 16, and an amino acid which is substituted due to the mutation. For example, F87A means a CYP102A1 mutant in which phenylalanine (F) (87th amino acid of SEQ ID NO: 16 which is the amino acid sequence of the wild-type CYP102A1) is substituted with valine (V) by natural or artificial mutagenesis. When the amino acid substituted by the mutation in the mutant is at least one, the amino acid may be represented by ‘/’. For example, F87A/A264G means a mutant of CYP102A1 in which phenylalanine (F) (87th amino acid of SEQ ID NO: 16) is substituted with valine (V), and alanine (A) (264th amino acid of SEQ ID NO: 16) is substituted with glycine (G). The above-described representation of the mutants may be used to represent the mutation of CYP102A1 chimera or the mutants of CYP102A1 chimera in the present invention.
In the present invention, the CYP102A1 chimera may be produced by fusing the heme domain of the CYP102A 1 mutant with the reductase domain of the natural variant of the wild-type CYP102A1.
According to an exemplary embodiment of the present invention, the CYP102A1 chimera may include sequences changed by at least one substitution selected from the group consisting of an alanine (A) (475th amino acid) to valine (V) substitution, a glutamic acid (E) (559th amino acid) to aspartic acid (D) substitution, a threonine (T) (665th amino acid) to alanine (A) substitution, a proline (P) (676th amino acid) to leucine (L) substitution, an alanine (A) (679th amino acid) to glutamic acid (E) substitution, a glutamic acid (E) (688th amino acid) to alanine (A) substitution, an alanine (A) (742th amino acid) to glycine (G) substitution, a lysine (K) (814th amino acid) to glutamic acid (E) substitution, an arginine (R) (826th amino acid) to serine (S) substitution, an arginine (R) (837th amino acid) to histidine (H) substitution, a glutamic acid (E) (871th amino acid) to asparagine (N) substitution, an isoleucine (I) (882th amino acid) to valine (V) substitution, a glutamic acid (E) (888th amino acid) to glycine (G) substitution, a proline (P) (895th amino acid) to serine (S) substitution, a serine (S) (955th amino acid) to asparagine (N) substitution, a methionine (M) (968th amino acid) to valine (V), a glutamine (Q) (982th amino acid) to arginine (R) substitution, an alanine (A) (1009th amino acid) to aspartic acid (D) substitution, a histidine (H) (1022th amino acid) to tyrosine (Y) substitution, and a glutamine (Q) (1023th amino acid) to glutamic acid (E) substitution, in the reductase domain of the CYP102A mutant.
In the present invention, the preferable CYP102A1 chimera may be R47L/F81 I/F87V/E143G/L188Q/E267V/A475V/E559D/T665A/P676L/A679E/E688A/A742G/K814E/R826S/R837H/E871N/I882V/E888G/P895S/S955N/M968V/Q982R/A1009D/H1022Y/Q1023E of the CYP102A1 mutant, but the present invention is not limited thereto.
In the present invention, the mutant of CYP102A1 chimera may be selected from mutants induced from the CYP102A1 chimera.
According to an exemplary embodiment of the present invention, the mutant of CYP102A1 chimera may include sequences changed by at least one substitution selected from the group consisting of a phenylalanine (f) (11th amino acid of CYP102A1 chimera) to leucine (L) substitution, an arginine (R) (47th amino acid) to leucine (L) substitution, a phenylalanine (F) (81th amino acid) to isoleucine (I) substitution, a phenylalanine (F) (87th amino acid) to valine (V) substitution, a leucine (L) (103th amino acid) to phenylalanine (F) substitution, a glutamine (Q) (110th amino acid) to proline (P) substitution, a methionine (M) (112th amino acid) to threonine (T) substitution, an aspartic acid (D) (136th amino acid) to glycine (G) substitution, glutamic acid (E) (143th amino acid) to glycine (G) substitution, asparagine (N) (159th amino acid) to serine (S) substitution, leucine (L) (188th amino acid) to glutamine (Q) substitution, an arginine (R) (190th amino acid) to glutamine (Q) substitution, a glutamic acid (E) (267th amino acid) to valine (V) substitution, and a methionine (M) (417th amino acid) to threonine (T) substitution.
In the present invention, the mutant of the preferable CYP102A1 chimera may be selected from the group consisting of F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/E267V, R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/E267V, and R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T of the CYP102A1 chimera, but the present invention is not limited thereto.
According to an exemplary embodiment of the present invention, the astringin which is 3′-hydroxypolydatin may be produced from the polydatin by at least one enzyme of the group consisting of the mutants of CYP102A1 chimera and the CYP102A1 chimera, which may be confirmed by methods such as HPLC (FIG. 1), LC-MS spectrum (FIG. 2), and NMR spectra (FIG. 4). In addition, it may be appreciated that the mutants of the CYP102A1 chimera have higher molecular catalytic activity than the CYP102A1 chimera.
In the present invention, the wild-type CYP102A1, the CYP102A1 mutant, the CYP102A1 chimera and the mutant of CYP102A1 chimera may be produced by methods known in the art. For example, the production methods may include genetic engineering technique, peptide synthesis using solid-phase technique (Merrifield, J. Am. Chem. Soc., 85: 2149-2154 (1963)), a method of cutting the enzymes of the present invention by an appropriate peptidase, and the like.
In the present invention, the enzymes may be produced as natural protein, and may be produced by a recombinant method including culturing and recovering cells transformed with DNA encoding the wild-type CYP102A1, the CYP102A1 mutant, the CYP102A1 chimera, and the mutants of CYP102A1 chimera. Specifically, the enzymes of the present invention may be produced by inserting nucleic acid molecules encoding the enzymes of the present invention into a suitable expression vector, delivering the expression vector to an appropriate cell to form a transformant, culturing the transformant, and purifying the enzymes expressed by the transformant.
In the present invention, the vector may be a plasmid, cosmid, virus particle, or phage.
Example of a host cell cloning or expressing DNA in the vector may include a prokaryotic cell, yeast and a higher eukaryotic cell. Culture conditions such as medium, temperature, pH, and the like, may be appropriately selected without undue experiments in the art to which the invention pertains. For example, principles, protocols, techniques, and the like, for maximizing productivity of cell culture may be used with reference to Mammalian Cell Biotechnology: A Practical Approach, M. Butler, ed. (IRL Press, 1991) among a number of known methods.
In the present invention, expression and cloning vectors may generally include promoters operably linked to a nucleic acid sequence encoding the wild-type CYP102A1 inducing mRNA synthesis, the CYP102A1 mutant, the CYP102A1 chimera and the mutants of CYP102A1 chimera. Various promoters recognized by the host cell are known. Examples of the promoter appropriate for being used in prokaryotic hosts include β-lactamase and lactose promoter system, alkaline phosphatase, a tryptophan promoter system, and a hybrid promoter, for example, a tac promoter. A promoter used in a bacterial system may include Shine-Dalgarno (S.D.) sequence operably linked to DNA encoding SISP-1. Examples of the promoter sequence appropriate for being used in a yeast host may include 3-phosphoglycerate kinase or other glycolytic enzymes.
The present invention provides a method for producing astringin including: reacting at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, using polydatin as a substrate.
The present invention provides the method for producing astringin including: reacting at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, using polydatin as a substrate, wherein the CYP102A1 chimera is R47L/F81I/F87V/E143G/L188Q/E267V/A475V/E559D/T665A/P676L/A679E/E688A/A742G/K814E/R826S/R837H/E871N/I882V/E888G/P895S/S955N/M968V/Q982R/A1009D/H1022Y/Q1023E of a CYP102A1 mutant, the CYP102A1 mutant is R47L/F81I/F87V/E143G/L188Q/E267V of a wild-type CYP102A1, and the mutant of CYP102A1 chimera is at least one selected from the group consisting of F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/E267V, R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/E267V, and R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T of the CYP102A1 chimera.
The method for producing astringin in the present invention may further include: an NADPH-generating system.
The NADPH-generating system in the present invention may be the same as known in the art. Preferably, glucose 6-phosphate, NADPH- and yeast glucose 6-phosphate dehydrogenase may be used, but the present invention is not limited thereto.
The present invention may provide a kit for producing astringin including at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, and an NADPH-generating system.
The present invention may provide the kit for producing astringin including at least one enzyme of the group consisting of mutants of CYP102A1 chimera and the CYP102A1 chimera, and an NADPH-generating system, and producing astringin by oxidizing polydatin, wherein the CYP102A1 chimera is R47L/F81I/F87V/E143G/L188Q/E267V/A475V/E559D/T665A/P676L/A679E/E688A/A742G/K814E/R826S/R837H/E871N/882V/E888G/P895S/S955N/M968V/Q982R/A1009D/H1022Y/Q1023E of a CYP102A1 mutant, the CYP102A1 mutant is R47L/F81I/F87V/E143G/L188Q/E267V of a wild-type CYP102A1, and the mutant of CYP102A1 chimera is at least one selected from the group consisting of F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/E267V, R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/E267V, and R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T of the CYP102A1 chimera.
The kit according to the present invention may further include reagents required for performing the reaction for producing the astringin.
With the composition for producing the astringin, the kit, and the production method according to the present invention, the astringin which is the metabolite of polydatin that is not capable of being chemically synthesized may be economically mass-produced at high yield, thereby being effectively usable for various research and drug development.
Hereinafter, the present invention is specifically described by Examples. The following Examples are provided as an example for practicing the present invention, and therefore, the present invention is not limited to the following Examples.
EXAMPLE 1
Construction of P450 BM3 Mutant by Site-Directed Mutagenesis
Seventeen (17) CYP102A1 site-directed mutants were constructed by the same method as a method described in research paper (see Generation of Human Metabolites of 7-Ethoxycoumarin by Bacterial Cytochrome P450 BM3. Drug Metabolism and Disposition 36(11):2166-2170. Page 2 (Page 2167), Materials and Methods, Construction of BM3 Mutants by Site-directed Mutagenesis, written by Kim D. H., Kim K. H., Kim D. H., Liu K. H., Jung H. C., Pan J. G., and Yun C. H. (2008)). Primers used for introducing BanHI/SacI restriction sites and PCR primers (XENOTECH, Korea) for inducing mutations were shown in Table 1. Codons for amino acid substitution were expressed in italics and underlines. The genes encoding CYP102A1 mutants were amplified from pCWBM3 by PCR using primers designed for facilitate cloning into expression vector pCWori (obtained by Dr. F. W. Dahlquist, University of California, Santa Barbara, Calif.) or pSE420 (Invitrogen) (see Chimeric Cytochromes P450 Engineered by Domain Swapping and Random Mutagenesis for Producing Human Metabolites of Drugs, Biotechnology and Bioengineering 111(7):1313-1322. Page 1315, written by Kang J. Y., Ryu S. H., Park S. H., Cha G. S., Kim D. H., Kim K. H., Hong A. W., Ahn T., Pan J. G., Joung Y. H., Kang H. S., and Yun C. H. (2014)). Oligonucleotide assembly was performed by using the primers shown in Table 1. The amplified genes were cloned into the BamHI/SacI restriction sites of PCWBM3 BamHI/SacI vector. The plasmids were transformed into Escherichia coli DH5α F′-IQ (Invitrogen) and were also used to express the CYP102A1 mutant protein. After mutagenesis, the presence of the desired mutations was confirmed by DNA sequencing (XENOTECH, Korea). The wild-type CYP102A1 amino acid sequence (SEQ ID NO: 16) used for the construction of P450 BM3 mutant was the same as being shown in FIG. 6. In accordance with the convention, the first amino acid, methionine (M), was not included in the amino acid sequence, and threonine (T) was calculated as the first amino acid.











name
sequence







BamHi forward 
5′-AGC GGA TCC ATG ACA ATT AAA 


(SEQ ID NO: 1)
GAA ATG CCT C-3′


 


SacI
5′-ATC GAG CTC GTA GTT TGT AT-3′


(SEQ ID NO: 2)



 


R47L
5′-GCG CCT GGT CTG GTA ACG CG-3′


(SEQ ID NO: 3)



 


Y51F
5′-GTA ACG CGC TTC TTA TCA AGT-3′


(SEQ ID NO: 4)



 


E64G
5′-GCA TGC GAT GGC TCA CGC TTT-3′


(SEQ ID NO: 5)



 


a74G
5′-TA AGT CAA GGC CTT AAA TTT GTA


(SEQ ID NO: 6)
CG-3′


 


F81I
5′-GTA CGT GAT ATT GCA GGA GAC-3′


(SEQ ID NO: 7)



 


L86I
5′-GGA GAC GGG ATT TTT ACA AGC T-


(SEQ ID NO: 8)
3′


 


F87A
5′-GAC GGG TTA GCG ACA AGC TCG-3′


(SEQ ID NO: 9)



 


F87V
5′-GAC GGG TTA GTG ACA AGC TGG-3′


(SEQ ID NO: 10)



 


E143G
5′-GAA GTA CCG GGC GAC ATG ACA-3′


(SEQ ID NO: 11)



 


L188Q
5′-ATG AAC AAG CAG CAG CGA GCA A-


(SEQ ID NO: 12)
3′


 


A264G
5′-TTC TTA ATT GGG GGA CAC GTG-3′


(SEQ ID NO: 13)



 


E264G
5′-T GCG GGA CAC GTG ACA ACA AGT-


(SEQ ID NO: 14)
3′


 


L86I/F87V
5′-GGA GAC GGG ATT GTG ACA AGC


(SEQ ID NO: 15)
TG-3′









EXAMPLE 2
Expression and Purification of Wild-Type CYP102A1 and Mutant Thereof
The plasmids including genes of the wild-type CYP102A1(pCWBM3) and the CYP102A1 mutants were transformed into Escherichia coli DH5α F′-IQ (Invitrogen) (see Kim et al., 2008). The culture was inoculated from a single colony into 5 ml of Luria-Bertani medium supplemented with ampicillin (100 μg/ml) and incubated at 37° C. After the culture, the obtained culture was inoculated into 250 ml of Terrific Broth medium supplemented with ampicillin (100 μg/ml), and was incubated at 37° C. with shaking at 250 rpm up to 0.8 at OD600, and gene expression was induced by adding isopropyl-β-D-thiogalactopyranoside (IPTG) so as to have a final concentration of 0.5 mM, and δ-aminolevulinic acid (0.1 mM) was added thereto. After the expression was induced, the culture was further incubated at 30° C. for another 36 hours, and cells were harvested by centrifugation (15 minutes, 5,000 g, 4° C.). The cell pellet was obtained and re-suspended with TES buffer (100 mM Tris-HCl, pH 7.6, 500 mM sucrose, 0.5 mM EDTA), and the cells were lysed by sonication (sonicator; Misonix, Inc., Farmingdale, N.Y.). After the cell lysate was centrifuged under conditions of 100,000 g, 90 minutes and 4° C., soluble cytosolic fraction was collected to measure activity. The cytosolic fraction was dialyzed into a 50 mM potassium phosphate buffer (pH 7.4) and stored at −80° C., and the enzymes within 1 month after preparation were used for the experiment.
The concentration of CYP102A1 was determined by CO-difference spectrum, wherein ε is 91 mM/cm (Omura and Sato, 1964). In all of the wild-type CYP102A1 and the CYP102A1 mutants, the culture generally yielding 300 to 700 nM P450 could be generally obtained. An expression level of the wild-type CYP102A1 and the mutants thereof had a cytoplasmic protein range of 1.0 to 2.0 nmol P450/mg. Among the constructed mutants, the mutants having high catalytic activity to some substrates in human could be selected, and sites having the substitution of amino acids in each mutant were shown in Table 2.







TABLE 2





CYP102A1 mutants used in the present invention

















Mutant #1
F87A
Carmichael et al., 2001


Mutant #2
A264G
Carmichael et al., 2001


Mutant #3
F87A/A264G
Carmichael et al., 2001


Mutant #4
R47L/Y51F
Carmichael et al., 2001


Mutant #5
R47L/Y51F/A264G
Carmichael et al., 2001


Mutant #6
R47L/Y51F/F87A
Carmichael et al., 2001


Mutant #7
R47L/Y51F/F87A/A264G
Carmichael et al., 2001


Mutant #8
A74G/F87V/L188Q
Li et al., 2001


Mutant #9
R47L/L86I/L188Q
Kim et al., 2008a


Mutant #10
R47L/F87V/L188Q
van Vugt Lusenburg




et al., 2007


Mutant #11
R47L/F87V/L188Q/E267V
van Vugt Lusenburg




et al., 2007


Mutant #12
R47L/L86I/L188Q/E267V
Kim et al., 2008


Mutant #13
R47L/L86I/F87V/L188Q
van Vugt Lusenburg




et al., 2007


Mutant #14
R47L/F87V/E143G/L188Q/
Kim et al., 2008a



E267V


Mutant #15
R47L/E64G/F87V/E143G/
Kim et al., 2008a



L188Q/E267V


Mutant #16
R47L/F81I/F87V/E143G/
Kim et al., 2008a



L188Q/E267V


Mutant #17
R47L/E64G/F81I/F87V/E143G/
van Vugt Lusenburg



L188Q/E267V
et al., 2007









(Ref. Kim D. H., Kim K. H., Isin E. M., Guengerich F. P., Chae H. Z., Ahn T., and Yun C. H. (2008a) Heterologous Expression and Characterization of Wild-Type Human Cytochrome P450 1A2 Without Conventional N-Terminal Modification in Escherichia Coli. Protein Expr Purif. 57:188-200.)
EXAMPLE 3
Construction and Expression of CYP102A1 Chimera
Selective CYP102A1 chimera protein was constructed by fusing the heme domain of the CYP102A1 mutant shown in Table 2 with the reductase domain of the natural variant of the wild-type CYP102A1. Mutant#16 mutant was used as the CYP102A1 mutant, and natural mutants (Table 3) of Bacillus megaterium species were used as natural variants.
For the heme domain and the reductase domain, the CYP102A1 chimera constructed by using BamHI/SacI was cloned into the expression vector pCW vector. Specifically, gene segments including the Mutant#16 mutant were separated from the heme domain gene by treating each plasmid of the Mutant#16 mutant constructed by Examples 1 and 2 with BamHI/SacI restriction enzymes. M16V3 which is the chimera protein of the natural variant CYP102A1.3 and Mutant#16 including Mutant#16 mutant was produced by adding BamHI/SacI restriction enzyme to the plasmids of Mutant#16 mutant in DNA segments obtained by treating natural variants CYP102A1.3(KCCM 12503) with BamHI/SacI restriction enzyme. The nucleic acid and amino acid sequences of M16V3 were shown in FIGS. 7 and 8, respectively.
The plasmids including genes of CYP102A1 chimera were transformed into Escherichia coli DH5α F′-IQ (Invitrogen) (Kim et al., Protein Expr. Purif. 57:188-200, 2008). The culture was inoculated from a single colony into 5 ml of Luria-Bertani medium supplemented with ampicillin (100 μg/ml) and incubated at 37° C. After the culture, the obtained culture was inoculated into 250 ml of Terrific Broth medium supplemented with ampicillin (100 μg/ml), and incubated at 37° C. with shaking at 250 rpm up to 0.8 at OD600, and gene expression was induced by adding isopropyl-β-D-thiogalactopyranoside (IPTG) so as to have a final concentration of 0.5 mM, and δ-aminolevulinic acid (0.1 mM) was added thereto. After the expression was induced, the culture was further incubated at 30° C. for another 36 hours, and cells were harvested by centrifugation (15 minutes, 5,000 g, 4° C.). The cell pellet was obtained and re-suspended with TES buffer (100 mM Tris-HCl, pH 7.6, 500 mM sucrose, 0.5 mM EDTA), and the cells were lysed by sonication (sonicator; Misonix, Inc., Farmingdale, N.Y.). After the cell lysate was centrifuged under conditions of 100,000 g, 90 minutes and 4° C., soluble cytosolic fraction was collected to measure activity. The cytosolic fraction was dialyzed into a 50 mM potassium phosphate buffer (pH 7.4) and stored at −80° C., and the enzymes within 1 month after preparation were used for the experiment.
The concentration of CYP102A1 chimera was determined by CO-difference spectrum, wherein ε is 91 mM/cm (Omura and Sato. J. Biol. Chem. 239:2379-2385, 1964).In the CYP102A1 chimera, the culture generally yielding 300 to 700 nM P450 could be obtained. The expression level of CYP102A1 chimera had a cytoplasmic protein range of 1.0 to 2.0 nmol P450/mg. Among the constructed CYP102A1 chimeras, the chimeras having high catalytic activity to some substrates in human could be selected, and sites having the substitution of amino acids in the CYP102A1 chimeras were shown in Table 4.







TABLE 3







Natural mutants used in the present invention









Accession Number












Variant
Genomic
16S
16S-23S


Strain
Nameb
DNA
rRNA
intergenic





KCCM 11745
102A1.1
(J04832)c
FJ917385
FJ969781


IFO 12108
102A1.1
(J04832)c
FJ969756
FJ969774


ATCC 14581
102A1.1
(J04832)c
FJ969751
FJ969767


KCCM 41415
102A1.1
(J04832)c
FJ969762
FJ969792


KCTC 3712
102A1.2
FJ899078
FJ969764
FJ969795


KCCM 12503
102A1.3
FJ899082
FJ969761
FJ969787


ATCC 15451
102A1.4
FJ899085
FJ969753
FJ969768


ATCC 10778
102A1.5
FJ899078
FJ969746
FJ969765


KCCM 11938
102A1.5
FJ899078
FJ969760
FJ969786


KCCM 11761
102A1.5
FJ899078
FJ969757
FJ969783


KCCM 11776
102A1.6
FJ899081
FJ969758
FJ969784


KCCM 11934
102A1.6
FJ899081
FJ969759
FJ969785


ATCC 14945
102A1.7
FJ899084
FJ969749
FJ969766


ATCC 21916
102A1.8
FJ899092
FJ969755
FJ969772


KCTC 2194
102A1.8
FJ859036
FJ969763
FJ969794


ATCC 19213
102A1.9
FJ899091
FJ969754
FJ969769
















TABLE 4







Chimera (M16V3) of CYP102A1 mutant used in the present invention









Abbreviations
BM3 mutant
Ref





Variant3(V3)
A475V/E559D/T665A/P676L/A679E/
Kang et al.



E688A/A742G/K814E/R826S/R837H/
2011



E871N/I882V/E888G/P895S/S955N/



M968V/Q982R/A1009D/H1022Y/Q1023E









(Ref.: AMB Express 1(1):1. Kang J. Y.1, Kim S. Y., Kim D., Kim D. H., Shin S. M., Park S. H., Kim K. H., Jung H. C., Pan J. G., Joung Y. H., Chi Y. T., Chae H. Z., Ahn T., Yun C. H. (2011) Characterization of Diverse Natural Variants of CYP102A1 Found Within A Species of Bacillus Megaterium)
EXAMPLE 4
Construction of Mutant of CYP102A1 Chimera by Site-Directed Mutagenesis
Three (3) different site-directed mutants of the CYP102A1 chimera were constructed by the same method as described in the research paper (see Generation of Human Metabolites of 7-Ethoxycoumarin by Bacterial Cytochrome P450 BM3. Drug Metabolism and Disposition 36(11):2166-2170. Page 2 (Page 2167), Materials and Methods, Construction of BM3 Mutants by Site-directed Mutagenesis, written by Kim D. H., Kim K. H., Kim D. H., Liu K. H., Jung H. C., Pan J. G., and Yun C. H. (2008)). Primers used for introducing BanHI/SacI recognition sites and PCR primers (XENOTECH, Korea) for inducing mutations were shown in Table 1. Codons for amino acid substitution were expressed in italics and underlines. The genes encoding the mutants of CYP102A1 chimera were amplified from pCWBM3 by PCR using primers designed for facilitating cloning into expression vector pCWori (obtained by Dr. F. W. Dahlquist, University of California, Santa Barbara, Calif.) or pSE420 (Invitrogen) (see Chimeric cytochromes P450 engineered by domain swapping and random mutagenesis for producing human metabolites of drugs. Biotechnology and Bioengineering 111(7):1313-1322, Page 1315, written by Kang J. Y., Ryu S. H., Park S. H., Cha G. S., Kim D. H., Kim K. H., Hong A. W., Ahn T., Pan J. G., Joung Y. H., Kang H. S., and Yun C. H. (2014)). Oligonucleotide assembly was performed by using the primers shown in Table 1. The amplified genes were cloned into the BamHI/SacI recognition site of pCWBM BamHI/SacI vector. The plasmids were transformed into Escherichia coli DH5α F′-IQ (Invitrogen) and were also used to express the mutant protein of CYP102A1 chimera. After mutagenesis, the presence of the desired mutations was confirmed by DNA sequencing (XENOTECH, Korea).
EXAMPLE 5
Expression and Purification of Mutant of CYP102A1 Chimera
The plasmids including the mutant gene of CYP102A1 chimera were transformed into Escherichia coli DH5α F′-IQ (Invitrogen). The culture was inoculated from a single colony into 5 ml of Luria-Bertani medium supplemented with ampicillin (100 μg/ml) and incubated at 37° C.
After the culture, the obtained culture was inoculated into 250 ml of Terrific Broth medium supplemented with ampicillin (100 μg/ml), and was incubated at 37° C. with shaking at 250 rpm up to 0.8 at OD600, and gene expression was induced by adding isopropyl-β-D-thiogalactopyranoside (IPTG) so as to have a final concentration of 0.5 mM, and δ-aminolevulinic acid (0.1 mM) was added thereto. After the expression was induced, the culturing was additionally performed at 30° C. for another 36 hours, and centrifugation (15 minutes, 5,000 g, 4° C.) was performed, thereby harvesting cells. The cell pellet was obtained and re-suspended with TES buffer (100 mM Tris-HCl, pH 7.6, 500 mM sucrose, 0.5 mM EDTA), and the cells were lysed by sonication (sonicator; Misonix, Inc., Farmingdale, N.Y.). After the cell lysate was centrifuged under conditions of 100,000 g, 90 minutes and 4° C., soluble cytosolic fraction was collected to measure activity. The cytosolic fraction was dialyzed into a 50 mM potassium phosphate buffer (pH 7.4) and stored at −80° C., and the enzymes within 1 month after preparation were used for the experiment.
Mutants of CYP102A1 chimera concentration was determined by CO-difference spectrum, wherein ε is 91 mM/cm (Omura and Sato, 1964). In all of the wild-type CYP102A1 and the mutants of CYP102A1 chimera, the culture yielding 300 to 700 nM P450 could be generally obtained. An expression level of the wild-type CYP102A1 and the mutants of CYP102A1 chimera had a cytoplasmic protein range of 1.0 to 2.0 nmol P450/mg. Among the constructed mutants, the mutants having high catalytic activity to some substrates in human could be selected, and sites having the substitution of amino acids in each mutant were shown in Table 5.







TABLE 5







Mutants of CYP102A1 chimera used in the present invention








Abbreviations
BM3 mutant





387
F11L/R47L/F81I/F87V/Q110P/E143G/L188Q/R190Q/



E267V


380
R47L/F81I/F87V/L103F/D136G/E143G/N159S/L188Q/



E267V


306
R47L/F81I/F87V/M112T/E143G/L188Q/E267V/M417T









EXAMPLE 6
Confirmation of Oxidation of Polydatin
It was confirmed whether polydatin is oxidized in the wild-type CYP102A1, the CYP102A1 mutant, the CYP102A1 chimera, or the mutants of CYP102A1 chimera.
P450 BM3 50 pmol and 100 μl of polydatin as a substrate were added to 0.25 ml of 100 mM potassium phosphate buffer (pH 7.4) to perform a typical steady-state reaction. In order to start the reaction, the NADPH-generating system (10 mM glucose 6-phosphate, 0.5 mM NADP+ and 1 IU yeast glucose 6-phosphate-dihydrogenase per 1 ml of final concentration) was added. 20 mM polydatin solution was prepared with DMSO, and diluted with an enzyme reaction solution, thereby preparing a reaction mixture so that the final organic solvent has a concentration of 1%/(v/v) or less. The solution was reacted at 37° C. for 30 minutes, and the reaction was terminated with ethyl-acetate which is cooled by using ice with twice amount.
HPLC Analysis
The reaction mixture was centrifuged, the supernatant was removed and discarded. Then, the solvent was evaporated under a nitrogen gas, and analyzed by HPLC. A sample (30 μl) was injected into Gemini C18 column (4.6 mm×150 mm, 5 μm, Phenomenex, Torrance, Calif.). As mobile phase, 85% A (acetonitrile/0.5%:acetic acid=5:95, v/v), 15% B (acetonitrile/0.5%:acetic acid=95:5) were used. The mobile phase flowed at a rate of 1 ml/minute and an eluent was measured by 320 nm of UV.
In order to examine whether polydatin is oxidized by CYP102A1(P450 BM3), oxidativity of polydatin was measured at a substrate concentration fixed to be 1000 μM in the P450 wild-type CYP102A1, the CYP102A1 mutant, the CYP102A1 chimera, and the mutant of CYP102A1 chimera.
FIG. 1 shows HPLC chromatogram of polydatin metabolites produced by the wild-type bacteria CYP102A1, the CYP102A1 mutant, the CYP102A1 chimera, and the mutant of CYP102A1 chimera. Referring to FIG. 1, the peak of new metabolites could be confirmed by comparing the peak with the NADPH-generating system with the peak without the NADPH-generating system. In addition, efficiency for producing the metabolites by selecting CYP102A1 chimera (M16V3) and three mutants (387, 380, 306) of CYP102A1 chimera were compared with each other by using kinetic parameter.







TABLE 6







Kinetic parameter of CYP102A1 chimera and mutants of


CYP102A1 chimera









Astringin formation















kcat/Km




kcat
Km
(relative catalytic



CYP102A1
min−1
μM
efficiency)

















M16V3
0.25 ± 0.03
390 ± 111
0.00064
(1)



387
10.5 ± 0.4 
475 ± 39 
0.0221
(35)



380
4.3 ± 0.5
481 ± 137
0.0089
(14)



306
4.9 ± 0.8
398 ± 116
0.012
(19)










LC-MS Analysis and NMR Analysis
In order to identify the metabolites of polydatin produced by the mutants of CYP102A1 chimera, LC-MS analysis was conducted by comparing polydatin and the metabolites according to LC profile and fragmentation patterns, and production of 3′-hydroxypolydatin (astringin) by the mutants of CYP102A1 chimera was confirmed by the LC-MS analysis of the reaction mixture including the mutant of CYP102A1 chimera.
The mutants of CYP102A1 chimera were reacted at 37° C. for 30 minutes in the presence of 1000 μM of polydatin and the NADPH-generating system. The reaction was terminated by adding twice amount of ethyl acetate which is cooled by ice. After centrifugation, the supernatant was removed and discarded, and the organic solvent layer was dried in the presence of nitrogen. The reactant was re-constituted into a vortex mixing with 100 μl of the mobile phase and was subjected to sonication for 20 seconds. An appropriate amount 5 μl of the prepared solution was injected into an LC column. The LC-MS analysis was conducted by Shimadzu LCMS-2010 EV system (Shimadzu, Kyoto, Japan) having an LC-MS software installed therein at an electro spray ionization(positive) mode. In the Shim-pack VP-ODS column (4.6 mm×150 mm i.d.; Shimadzu co., Japan), 85% A (acetonitrile/0.5%:acetic acid=5:95, v/v), 15% B (acetonitrile/0.5%:acetic acid=95:5) were used as mobile phases. The mobile phases were separated at a rate of 0.1 ml/min. In order to confirm the metabolite, mass spectra were recorded at an electro spray ionization (positive) mode. The interface and the detector volt were 4.4 kV and 1.5 kV, respectively. A nebulization gas rate was set to be 1.5 ml/min, and an interface, a curve desolvation line (CDL) and a heat-block temperature were set to be 250° C., 250° C. and 200° C., respectively.
FIG. 2 shows LC-MS elution profiles of polydatin and metabolites thereof, produced by the mutant 387 of CYP102A1 chimera. It shows total ion current (TIC) profile of the metabolites produced by the mutant 387 of CYP102A1 chimera. In the mass spectra of the reaction samples, peaks were shown at 5.182 min (3′-hydroxypolydatin), and 6.453 min (polydatin). 3′-hydroxypolydatin and polydatin produced by the mutant 387 of CYP102A1 chimera were observed at 407 and 391 ([M+H]+) in mass spectra, respectively.
FIG. 4 shows the structures of the metabolites produced by the mutant 387 of the bacteria CYP102A1 chimera, and it was confirmed that the obtained product was astringin which is 3′-hydroxypoladatin by NMR analysis.
According to the present invention, astringin among metabolites of polydatin is capable of being produced from polydatin by using the composition including a cytochrome P450 chimeric enzyme and mutants thereof, which may be an alternative method to produce astringin in which the chemical synthesis has not yet been reported. In addition, astringin which is piceatannol glucoside among the metabolites of polydatin is capable of being specifically produced by using the composition including the cytochrome P450 chimeric enzyme and the mutants thereof, thereby having process benefits.

## Claims

1. A composition for producing astringin from polydatin comprising a mutant of a CYP102A1 chimera,
wherein the mutant of the CYP102A1 chimera is F11L/F81I/Q110P/R190Q of the CYP102A1 chimera, and
wherein the CYP102A1 chimera consists of the amino acid sequence of SEQ ID NO: 18.

2. A kit for producing astringin from polydatin comprising a mutant of a CYP102A1 chimera and an NADPH-generating system,
wherein the mutant of the CYP102A1 chimera is F11L/F81I/Q110P/R190Q of the CYP102A1 chimera; and wherein the CYP120A1 chimera consists of the amino acid sequence of SEQ ID NO: 18.