Quick preparation method of mussel protein antihypertensive peptide
Technical Field
The invention belongs to the technical field of bioengineering, and particularly relates to a rapid preparation method of mussel protein antihypertensive peptide.
Background
Angiotensin Converting Enzyme (ACE), also known as peptidyl-carboxypeptidase or kininase II, has a molecular weight of 150,000Da and belongs to vascular endothelial cell membrane-binding enzymes. ACE hydrolyzes decapeptide angiotensin i to octapeptide angiotensin ii, causing further constriction of the blood vessels, resulting in elevated blood pressure. Also, ACE may promote aldosterone secretion by acting on the adrenal cortex. ACE is therefore an important component of renin-angiotensin-aldosterone (RAS). In addition, ACE can catalyze the hydrolysis of bradykinin with blood pressure lowering effect to make bradykinin lose activity. Therefore, the purpose of reducing or controlling blood pressure can be achieved by searching for a proper substance for inhibiting the ACE activity in the body.
Angiotensin Converting Enzyme Inhibitors (ACEI) are a class of rapidly developed antihypertensive drugs, which mainly inhibit the activity of ACE so that angiotensin I cannot be converted into angiotensin II, and inhibit the inactivation of bradykinin by ACE, thereby generating the antihypertensive effect. Angiotensin Converting Enzyme Inhibitors (ACEI) are often used as chemical drugs in clinical practice, such as Captopril (Captopril), Alacepril (Alacepril), Lisinopril (Lisinopril) and Fosinopril (Fosinopril). However, the chemical synthetic drugs have more side effects in clinical application, such as granulocytopenia, cough, rash, fever, abnormal taste and the like, which bring certain pains to patients.
Currently, ACE inhibitory active peptides (ACEPs) are widely regarded for their remarkable physiological activities, and the advantages of ACEPs compared to chemically synthesized ACEIs mainly reflected in: (1) the compound is prepared by adopting food-grade protease hydrolysis, has high safety and small toxic and side effects, and has no obvious toxic and side effects observed in a plurality of ACEP animal experiments and clinical test results; (2) the source of the edible protein raw material is wide, the enzymolysis preparation condition is mild, and the industrialization is easy; (3) ACEP has specific antihypertensive effect, low molecular weight and easy digestion and absorption. Therefore, research and development of active peptide food or medicine with the function of reducing blood pressure become an important way for high-efficiency utilization of aquatic products.
In recent years, magnetic microspheres have attracted considerable attention as carriers for immobilized enzymes. The agarose is modified by adopting an emulsification composite technology, and the prepared agarose magnetic microspheres have the following remarkable advantages: (1) the magnetic separation device has magnetism, and can rapidly separate under the action of a magnetic field; (2) the biocompatibility is good; (3) the surface contains a large number of functional groups, so that the adsorption capacity is strong; (4) has good dispersibility and stability. The agarose magnetic microspheres are used as a carrier, and the prepared magnetic microsphere immobilized ACE can be specifically adsorbed with ACEP in a solution and can be rapidly separated from an enzymolysis solution under the action of a magnetic field. However, researchers found that there is no research on the preparation of antihypertensive peptides from mussel zymolyte using this technique.
Based on the method, the mussel protein is degraded by adopting an enzymolysis technology, and the antihypertensive peptide is prepared by utilizing ultrafiltration, magnetic microsphere immobilized ACE adsorption and a high performance liquid chromatography technology, so that a new way is provided for high-value utilization of the mussels.
Disclosure of Invention
The technical problem to be solved by the invention is to provide a rapid preparation method of the mussel protein antihypertensive peptide with a remarkable inhibitory effect on Angiotensin Converting Enzyme (ACE).
The technical scheme adopted by the invention for solving the technical problems is as follows: a rapid preparation method of mussel protein antihypertensive peptide comprises the following steps:
1) preparing and activating agarose magnetic microspheres: adding 30mL of agarose into water according to the weight-volume ratio of 1-1.5 g, boiling the agarose together until the agarose is completely dissolved, and adding 1mL of Fe3O4The magnetic fluid is fully mixed on the vortex mixer; dropping the mixed solution into an organic phase (Span-80: liquid paraffin =1g:25 mL) at 80 ℃ under stirring, and reacting for 15-20 min at 80 ℃; cooling the organic phase to 40 ℃, mechanically stirring at a rotating speed of 250rpm for 10-15 min to form microspheres, separating in a magnetic field, and cleaning the prepared microspheres for 3 times by using petroleum ether and deionized water respectively to remove residual organic phase to obtain agarose magnetic microspheres; reacting NaBH4Adding the activated agarose magnetic microspheres into NaOH solution (0.8-1.0 mol/L) according to the weight-volume ratio of 2-3 mg:1mL, then adding epoxy chloropropane into the NaOH solution (0.8-1.0 mol/L) according to the volume ratio of 0.5-0.7: 1, finally adding the agarose magnetic microspheres into the NaOH solution (0.8-1.0 mol/L) according to the weight-volume ratio of 2-3 g:1mL, and stirring for 3-5 h at 40 ℃ to obtain the activated agarose magnetic microspheres.
) Fixation of ACE: adding Angiotensin Converting Enzyme (ACE) and activated agarose magnetic microspheres into borate buffer solution (0.1 mol/L) according to the mass ratio of 1-1.5: 10, oscillating at 40-50 ℃ for 2-3 h, putting the mixed solution into a magnetic field, separating the agarose magnetic microspheres, fully washing with distilled water until no enzyme protein is washed out, and carrying out vacuum freeze drying to obtain the agarose magnetic microsphere immobilized ACE.
) Enzymolysis and ultrafiltration of mussel protein, namely, shelling the mussels, mixing mussel meat with glycine-NaOH buffer solution according to the weight-volume ratio of 1g to 3-5 mL, homogenizing, adjusting the pH value to 9.5-10 to obtain mixed solution, adjusting the temperature of the mixed solution to 45-55 ℃, and adding alkaline protease (2.0 × 10) according to 0.5-0.8 percent of the mass of the mussel meat5U/g), enzymolysis for 4-6 h, heating the enzymolysis liquid to 90-95 ℃, keeping the temperature for 10-15 min, adjusting the temperature to 35-40 ℃, adjusting the pH to 8.5-9.0 by using 1mol/LNaOH solution, and adding trypsin (1.9 × 10) according to 0.8-1.0 percent of the mass of the mussel meat4U/g), performing enzymolysis for 4-6 h, performing ultrafiltration treatment on the enzymolysis liquid by using a 1kDa ultrafiltration membrane, collecting the part with the molecular weight less than 1kDa, and performing freeze-drying to obtain an ultrafiltration zymolyte.
) Preparing mussel protein antihypertensive peptide: and sequentially purifying the ultrafiltration zymolyte by agarose magnetic microsphere immobilized ACE adsorption and reversed phase high performance liquid chromatography (RP-HPLC) to obtain the antihypertensive peptide.
Preferably, the mussels in the step 3) are mytilus coruscus (Mytilus coruscus: (A)Mytilus coruscus)。
As an improvement, the agarose magnetic microsphere immobilized ACE adsorption and RP-HPLC purification in the step 4) are as follows:
adsorption of agarose magnetic microsphere immobilized ACE: adding NaCl into borate buffer solution (0.1 mol/L, pH 7.8) until the concentration is 0.2mol/L, then adding ultrafiltration zymolyte until the concentration is 5-8 mg/mL, finally adding agarose magnetic microsphere immobilized ACE according to 30-50 times of the weight of the zymolyte in the solution, adsorbing for 45min, separating the magnetic microspheres from the solution by using a magnetic field, repeatedly washing the microspheres by using the borate buffer solution until washing solution has no ultraviolet absorption at 220nm and 280nm, desorbing the magnetic microspheres in 1.0mol/L NaCl solution, separating the magnetic microspheres from the solution by using the magnetic field, and freeze-drying the solution to obtain the antihypertensive peptide mixture.
RP-HPLC purification: preparing a 45-55 mu g/mL solution of the antihypertensive peptide mixture, purifying by RP-HPLC, and obtaining the antihypertensive peptide Val-Ser-Trp-Pro-Cys-Arg-Trp (VSWPCRW) according to the ACE inhibitory activity.
Preferably, the RP-HPLC conditions are: the sample injection amount is 19-21 mu L; the chromatographic column is Zorbax C18 (250X 4.6mm, 5 μm); the mobile phase is 40% acetonitrile; the elution speed is 1.0 mL/min; the ultraviolet detection wavelength is 220 nm.
The method for preparing the antihypertensive peptide by carrying out enzymolysis on the mussel protein has the following advantages:
the invention adopts a biological enzyme method, which is easy to control the enzymolysis process, so that ACEP is released to the maximum extent, and the utilization rate of raw materials is improved. The prepared ACEP is prepared by carrying out enzymatic hydrolysis on mussel meat, is safe, has no toxic or side effect, has remarkable ACE inhibitory activity and has the effect of reducing blood pressure of patients with hypertension.
The product of the invention can be used as medicine, health food and the like, and has scientific and reasonable process, simple operation and stronger industrial implementation. Compared with the existing preparation method, the invention integrates multiple means of enzymolysis, ultrafiltration, magnetic microsphere immobilized enzyme adsorption and RP-HPLC at the same time, the method is more perfect, and the obtained antihypertensive peptide has higher activity.
Drawings
FIG. 1 is a chromatogram obtained when chromatography is carried out using a Zorbax C18 column in an example of the invention.
Detailed Description
The invention is described in further detail below with reference to the accompanying examples.
Example (b):
a method for rapidly preparing mussel protein antihypertensive peptide comprises the following preparation processes: the adsorption of the immobilized ACE of the mussel meat 'tissue disruption' enzymolysis 'ultrafiltration' agarose magnetic microspheres 'RP-HPLC purification' antihypertensive peptide.
) Preparing and activating agarose magnetic microspheres: adding agarose into water according to the weight-volume ratio of 1.5g:30mL, boiling until the agarose is completely dissolved, adding 1mL Fe3O4The magnetic fluid is fully mixed on the vortex mixer; mixing the mixed solution under stirringDropping into an organic phase (Span-80: liquid paraffin =1g:25 mL) at 80 ℃ and reacting at 80 ℃ for 20 min; cooling the organic phase to 40 ℃, mechanically stirring at the rotating speed of 250rpm for 15min to form microspheres, separating in a magnetic field, and respectively washing the prepared microspheres for 3 times by using petroleum ether and deionized water to remove residual organic phase to obtain agarose magnetic microspheres; reacting NaBH4Adding the solution into NaOH solution (0.8 mol/L) according to the weight-volume ratio of 2 mg:1mL, then adding epoxy chloropropane into the NaOH solution (0.8 mol/L) according to the volume ratio of 0.5: 1, finally adding agarose magnetic microspheres into the NaOH solution (0.8 mol/L) according to the weight-volume ratio of 3g:1mL, and stirring for 3h at 40 ℃ to obtain the activated agarose magnetic microspheres.
) Fixation of ACE: adding Angiotensin Converting Enzyme (ACE) and activated agarose magnetic microspheres into borate buffer solution (0.1 mol/L) according to the mass ratio of 1.5:10, oscillating at 50 ℃ for 3h, putting the mixed solution into a magnetic field, separating the agarose magnetic microspheres, fully washing with distilled water until no enzyme protein is washed out, and carrying out vacuum freeze drying to obtain the agarose magnetic microsphere immobilized ACE.
) Enzymolysis and ultrafiltration of mussel protein: mixing Mytilus coruscus (Mytilus coruscus, MyMytilus coruscus) Removing shell, mixing mussel meat with glycine-NaOH buffer solution at a weight volume ratio of 1g: 4 mL, homogenizing, adjusting pH to 9.5 to obtain mixed solution, adjusting temperature to 50 deg.C, and adding alkaline protease (2.0 × 10) 0.8% of mussel meat mass5U/g), performing enzymolysis for 5h, heating the enzymolysis solution to 95 deg.C, maintaining the temperature for 10 min, adjusting the temperature to 37 deg.C, adjusting pH to 8.6 with 1mol/L NaOH solution, and adding trypsin (1.9 × 10) according to 1.0% of the weight of mussel meat4U/g), performing enzymolysis for 6 hours, performing ultrafiltration treatment on the enzymolysis liquid by using a 1kDa ultrafiltration membrane, collecting the part with the molecular weight less than 1kDa, and performing freeze-drying to obtain the ultrafiltration zymolyte.
) Preparing mussel protein antihypertensive peptide: purifying the ultrafiltration zymolyte by agarose magnetic microsphere immobilized ACE adsorption and reversed phase high performance liquid chromatography (RP-HPLC) in sequence to obtain the antihypertensive peptide.
Adsorbing immobilized ACE by using agarose magnetic microspheres: adding NaCl into borate buffer solution (0.1 mol/L, pH 7.8) until the concentration is 0.2mol/L, then adding ultrafiltration zymolyte until the concentration is 6 mg/mL, finally adding agarose magnetic microsphere immobilized ACE according to 40 times of the weight of the zymolyte in the solution, adsorbing for 45min, separating the magnetic microspheres from the solution by using a magnetic field, repeatedly washing the microspheres by using the borate buffer solution until washing solution 220nm and 280nm have no ultraviolet absorption, desorbing the magnetic microspheres in 1.0mol/L NaCl solution, separating the magnetic microspheres from the solution by using the magnetic field, and freeze-drying the solution to obtain the antihypertensive peptide mixture.
② RP-HPLC purification: the mixture of antihypertensive peptides was formulated into 45. mu.g/mL solution, purified by RP-HPLC (conditions: sample size of 20. mu.L; chromatographic column: Zorbax C18 (250X 4.6mm, 5 μm), mobile phase of 40% acetonitrile, elution rate of 1.0mL/min, ultraviolet detection wavelength of 220 nm), and a highly active antihypertensive peptide was obtained from the inhibitory activity against ACE (see FIG. 1).
Structure detection: collecting the antihypertensive peptide with the highest activity, detecting the antihypertensive peptide as a single peak, determining the amino acid sequence to be Val-Ser-Trp-Pro-Cys-Arg-Trp (VSWPCRW) by using a protein/polypeptide sequence analyzer, and detecting the molecular weight to be 935.07Da by ESI/MS.
The mussel protein antihypertensive peptide Val-Ser-Trp-Pro-Cys-Arg-Trp (VSWPCRW) prepared in the above way is subjected to an ACE inhibitory activity experiment. The experimental results show that: half maximal Inhibition (IC) of the polypeptide50) The concentration was 37.53. + -. 1.09. mu.M.
Finally, it should also be noted that the above-mentioned list is only one specific embodiment of the invention. It is obvious that the invention is not limited to the above embodiments, but that many variations are possible. All modifications which can be derived or suggested by a person skilled in the art from the disclosure of the present invention are to be considered within the scope of the invention.
SEQUENCE LISTING
<110> Zhejiang ocean academy
Rapid preparation method of <120> mussel protein antihypertensive peptide
<130>zjou-wb-201504-4
<160>1
<170>PatentIn version 3.5
<210>1
<211>7
<212>PRT
<213> Artificial Synthesis
<400>1
Val Ser Trp Pro Cys Arg Trp
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