Background technology
The semi-synthetic industry of the twentieth century early stage beta-lactam antibiotics sixties is risen gradually, and this makes the parent nucleus 6-aminopenicillanic acid (6-APA) of beta-lactam become important medicinal intermediates.Therefore, people at first begin to synthesize 6-APA by penicillin acylase (PGA) cracking penicillin G.Subsequently, because the PGA unique selectivity, people are the selection katalysis of research and utilization PGA again, and removing acetoxyl Cephalosporanic acid (7-ADCA) with 6-APA or 7-amino is the parent nucleus of beta-lactam, adds suitable side chain and comes semi-synthetic beta-lactam antibiotics.
Over year, process is constantly screened and the PGA of gene recombination becomes more and more stable surplus in the of 40, and the throughput of enzyme also constantly is improved, and adds effective process for fixation and makes the recovery of enzyme become possibility, and the cost of this method is also reduced greatly.
Now, by this katalysis of enzyme, the whole world can produce 20000 tons 6-APA in 1 year, and corresponding β-Nei Xiananleikangshengsu, as Cephalexin Monohydrate Micro/Compacted, amoxycilline Trihydrate bp and S 578 etc. have realized gradually that also industrialized enzymatic is synthetic.
But it should be noted that effective PGA process for fixation is enzymatic lysis penicillin G and the semisynthetic key of beta-lactam antibiotics.So also quite pay attention to for the research in this field now.
Many materials all are studied and develop the immobilization that is used for carrying out penicillin acylase, and these materials of all things considered can be divided into three major types:
One, high molecular polymer: mainly be the porous resin material of some polyacrylic acid and derivatize thereof, representational as Eupergit C and Amberlite series plastics.
Two, biocompatible materials: this class mainly is that some are natural or have a material of certain biocompatibility, chitosan for example, dextran, sodium alginate, gelatin or the like.
Three, inorganic materials: this mainly is that some have porous inorganic materials, molecular sieve for example, diatomite or silica gel or the like.But this class material can carry out modification by some chemical processes usually.
These three kinds of materials have been widely used among the enzyme immobilization, be not only the fixing of penicillin acylase, but these three kinds of materials cut both ways.Usually in fact, the inorganic materials carrier has mechanical property and higher specific surface area preferably, and high molecular polymer then has higher immobilization efficiency and the rate of recovery and selectivity preferably.Biomaterial is then because their better biocompatibility, some helps are provided for immobilized enzyme, as improve their chemical stability, reduce the inactivation of enzyme in the immobilization process, but often the mechanical property of this class carrier is not very desirable, can not well adapt to for the reaction conditions of industrial harshness.
Summary of the invention
The invention provides a kind of preparation and carrying method that is used for fixing the carrier of penicillin acylase; with the high molecular polymer with certain active function groups is base material; absorption modification by chitosan and some auxiliary agents again; surface, carrier inside duct is modified; make surface, high molecular polymer carrier inside duct be more suitable for the absorption of enzyme and fixing, to obtain higher stability and active.
This preparation method who is used for fixing the carrier of penicillin acylase comprises the steps:
(1) porous resin that will have side chain functionalities grinds, screening, and drying, mix with chitosan solution the activation back, and oven dry obtains solid;
(2) solid that step (1) is obtained adds in the polar hydrophilic solvent, at mechanical stirring rotating speed 100~800r/min, after 10~100 minutes time, regulating the pH value is 7~11, adds auxiliary agent and carries out modification reaction, and modification reaction is suction filtration after 2~10 hours, washing, oven dry.
Described porous resin is granular solid porous resin, and particle diameter is 0.05~2.0mm, and the aperture is 2~100nm.
Described porous resin molecular skeleton is polypropylene, polystyrene, polyacrylic acid, polyethylene, polyacrylic ester, urethane etc., and the side chain functionalities that porous resin has is one or more in hydroxyl, amino, carboxyl, sulfonic group, thioureido, phosphonate group or the epoxy group(ing).
Described chitosan solution is that chitosan is dissolved in acetate or the hydrochloric acid soln, the mass percent concentration of chitosan is 0.5%~10.0%, described chitosan is biological level or technical grade chitosan, and removing the acetyl degree is 60%~95%, and molecular weight is 10000~500000.The mass ratio of described chitosan and resin is between 1: 1~1: 50.
Can be added with mass percent concentration in the described chitosan solution is 1.0%~10% hydrophilic material, and described hydrophilic material is polyoxyethylene glycol (PEG) 2000, polyoxyethylene glycol (PEG) 5000, polyoxyethylene glycol (PEG) 20000, dextran, Portugal's polyacetals or polyamine class.
Polar hydrophilic solvent described in the step (2) is one or more in water, dimethyl sulfoxide (DMSO) (DMSO), dimethyl formamide (DMF), acetone, methyl alcohol, the ethanol.
Auxiliary agent described in the step (2) is one or more in formaldehyde, acetaldehyde, glutaraldehyde, epoxy chloropropane, trimethoxy chloromethyl silane, aminopropyl triethoxysilane or the 2-chloroethyl amine/hydrochloride, and additive dosage is 1.0%~10% of a modification reaction system weight.
Press the method for the carrier loaded penicillin acylase of preparation method's preparation of the present invention, comprise the steps:
(a) described carrier is activated with inorganic assistant agent, described inorganic assistant agent is the aqueous solution of ammoniacal liquor, sodium bicarbonate, yellow soda ash or sodium polyphosphate, and concentration is 0.1~4.0mol/L, 20~70 ℃ of activation temperatures, soak time 6~20 hours;
(b) carrier after the inorganic assistant agent activation is activated with the bifunctional reagent, described bifunctional reagent is the aqueous solution of formaldehyde, oxalic dialdehyde or glutaraldehyde, mass percent concentration is 0.5%~5.0%, 20~70 ℃ of activation temperatures, soak time 1~8 hour;
(c) carrier after the activation was 20~70 ℃ of ageings of temperature 12~48 hours; with concentration is that the resolvase solution of 50~2000U/ml penicillin acylase mixes; 5~40 ℃ were reacted 12~60 hours; in system, add sodium borohydride; the sodium borohydride consumption of every milliliter of resolvase solution is 0.05~10mg, reaction 15~200min, suction filtration; washing, room temperature vacuum-drying can get fine particulate or pulverous immobilized penicillin amidase product.
The method of described carrier loaded penicillin acylase is equally applicable to some other kind of zymoid load; as long as the solution of the free penicillin acylase in the step (c) is changed into the solution of some other resolvase; as lytic enzyme, oxydo-reductase, synthetic enzyme or the like.Preferred L-Aminoacylase, porcine pancreatic lipase, tryptophan synthetase, urase.
In the step of the method for described load penicillin acylase (c), can determine the relation of carrier, resolvase solution usage as required, general every gram carrier uses 2~20 milliliters of resolvase solution.
Prepare carrier of the present invention and at first will select for use and a kind ofly have the macroporous particle resin as base material, for example, the Amberlite IRC76C of U.S. Rhom and Hass, Amberlite 1000Na; The D101 of domestic ion exchange resin universal models, D201, common resin such as D316.This macroporous resin contains certain functional group usually, as hydroxyl, and amino, carboxyl, sulfonic group, thioureido, phosphonate group, epoxy group(ing), and their derivatize group etc.Chitosan at first adsorbs in the duct of resin into by the porous adsorption, and the effect by different auxiliary agents is with its firm linking together with resin again.
Illustrate with three examples:
One is to be the resin and the covalently bound principle of chitosan of functional group with the hydroxyl, owing to have a lot of hydroxyls on the resin, therefore can pass through these hydroxyls, utilize the amino of trimethoxy (or triethoxy) chlorine alkyl silane and chitosan to have an effect, thereby reach the purpose of a modificationization, chitosan is fixed and is modified on the resin.
One is to be the resin and the covalently bound principle of chitosan of functional group with amino, owing to have a lot of amino on the resin, therefore can pass through these amino, utilize the crosslinked action of epoxy chloropropane, react with the amino of chitosan, thereby reach the purpose of a modificationization, chitosan is fixed and is modified on the resin.
One is to be the resin and the covalently bound principle of chitosan of functional group with the ester group, owing to have a lot of ester groups on the resin, therefore can pass through these ester groups, be added into two chlorethamins (hydrochloride) again, react with the ester group of chitosan, thereby reach the purpose of a modificationization, chitosan is fixed and is modified on the resin.
Like this, chitosan-modified porous resin carrier just can be prepared by these diverse ways, adopts common Covalent Immobilization method then, utilizes the amino of chitosan and bifunctional reagent's activation that enzyme is carried out Covalent Immobilization.
In this carrier, not only need to use the higher amino density of chitosan, provide basis and guarantee to covalent cross-linking, also need to utilize chitosan sugar ring to go up abundant hydroxyl, have only these hydroxyls a good wetting ability microenvironment is provided for the enzyme on fixing, could keep enzyme to have higher water activity like this, the enzyme deactivation rate is reduced greatly, keep a higher vigor stability.So this also is to adopt chitosan as one of free-revving engine of resin carrier modifier.
To sum up it seems, the first, the porous macroporous ion-exchange resin is that the absorption of chitosan and the absorption of enzyme provide the foundation; The second, the stable covalent modification of chitosan has improved the stability of whole carrier in resin surface; The 3rd, the abundant hydroxyl of chitosan provides a very good microenvironment for enzyme; The 4th, variable resin matrix makes fixation support have diversity to adapt to the demand of different enzymes and environment for use with functional group and different covalent modification processes.
Like this, both the biocompatibility effect by chitosan had kept enzyme self advantages of higher stability and activity, because there is high molecular polymer to have favorable mechanical performance and chemical stability, make whole immobilization product can adapt to harsh conditions in the beta-lactam antibiotics suitability for industrialized production preferably again as base material.
Embodiment
Embodiment 1
Get the spherical porous resin grinding of 5.0g polymethylmethacrylate and sieve to such an extent that particle diameter is the resin particle of 0.5mm.The 1.0g chitosan is dissolved in 2% acetic acid solution of 50ml, adds 0.5gPEG20000 again, be made into transparent settled solution.Resin and chitosan solution are mixed 40 ℃ of oven dry.Blended solid is changed in the round-bottomed flask, add 50ml water, mechanical stirring 200r/min, after 30 minutes, regulating the pH value with the NaOH aqueous solution is 10, adds 0.5g 2-chloroethyl amine hydrochloride, 40 ℃ of controlled temperature reacted after 5 hours, suction filtration, washing, 40 ℃ of oven dry.
Get carrier that 1.0g prepares in Erlenmeyer flask, add the sodium hydrogen carbonate solution of 1mol/L, 50 ℃ of temperature reacts 12 hours, separated, and added the glyoxal solution of 10ml 2.0% again, and shaking table vibrates, 200r/min, and temperature is controlled to be 40 ℃.Take out after 6 hours, 30 ℃ of ageings 24 hours add free penicillin acylase solution 400U/ml 5ml altogether, and 10 ℃ of reactions 24 hours add NaBH again in system
415mg, behind the processing 30min, suction filtration, washing, room temperature vacuum-drying.Separation can get the immobilized penicillin acylated enzyme product, and vigor is about 600~800U/g.
Embodiment 2
Get that 20.0g is poly-to be ground and sieve to such an extent that particle diameter is the resin particle of 0.5mm the spherical porous resin of vinylbenzene alkane hydroxyl.The 1.0g chitosan is dissolved in 1% hydrochloric acid soln of 50ml, adds 0.5gPEG2000 again, be made into transparent settled solution.Resin is mixed 40 ℃ of oven dry with chitosan solution.Blended solid is changed in the round-bottomed flask, add 50ml DMSO, after 30 minutes, mechanical stirring 500r/min, regulating the pH value with the NaOH aqueous solution is 9, adds the trimethoxy chloromethyl silane of 5ml, and 60 ℃ of controlled temperature react after 4 hours, suction filtration, washing, 40 ℃ of oven dry.
Get carrier that 1.0g prepares in Erlenmeyer flask, add the ammoniacal liquor of 1mol/L, 60 ℃ of temperature reacts 15 hours, separated, and added the glutaraldehyde solution of 10ml 2.0% again, and shaking table vibrates, 200r/min, and temperature is controlled to be 40 ℃.Take out after 4 hours, 30 ℃ of ageings 36 hours add free penicillin acylase solution 600U/ml 5ml altogether, and 20 ℃ of reactions 36 hours add NaBH again in system
410mg, behind the processing 60min, suction filtration, washing, room temperature vacuum-drying.Separation can get the immobilized penicillin acylated enzyme product, and vigor is about 500~700U/g.
Embodiment 3
Get the amino porous resin grinding of 10.0g polyacrylic acid uncle and sieve to such an extent that particle diameter is the resin particle of 0.5mm.1.0 chitosans are dissolved in 1% hydrochloric acid soln of 50ml, add 0.5g glucose again, be made into transparent settled solution.Resin and chitosan solution are mixed 40 ℃ of oven dry.Blended solid is changed in the round-bottomed flask, add 25ml DMF and 25ml ethanol, after 30 minutes, mechanical stirring 500r/min, regulating the pH value with the NaOH aqueous solution is 11, adds the epoxy chloropropane of 5ml, and 90 ℃ of controlled temperature react after 8 hours, suction filtration, washing, 50 ℃ of oven dry.
Get carrier that 1.0g prepares in Erlenmeyer flask, add the polyphosphoric acid sodium solution of 1mol/L, 30 ℃ of temperature reacts 12 hours, separated, and added the glyoxal solution of 10ml 2.0% again, and shaking table vibrates, 200r/min, and temperature is controlled to be 40 ℃.Take out after 6 hours, 30 ℃ of ageings 48 hours add free penicillin acylase solution and add free penicillin acylase solution 800U/ml 5ml altogether, and 30 ℃ of reactions 50 hours add NaBH again in system
420mg, behind the processing 150min, suction filtration, washing, room temperature vacuum-drying can get the immobilized penicillin acylated enzyme product, and vigor is about 700~900U/g.