Enzymolysis Efficiency Research Articles

Preparation of housefly (Musca domestica) larvae protein hydrolysates: Influence of dual-sweeping-frequency ultrasound-assisted enzymatic hydrolysis on yield, antioxidative activity, functional and structural attributes

Dual-sweeping-frequency ultrasound (DSFU) was utilized in the preparation of polypeptides from housefly (Musca domestica) larvae protein (HLP). Results indicated that ultrasonication (20 ± 2/28 ± 2 kHz, 42 W/L, 25 min) significantly increased peptide yield and DPPH scavenging capacity by 8.25 % and 14.83 %, respectively. Solubility, foaming and emulsification properties of polypeptides were improved by 19.89 %, 33.33 % and 38.74 % over the control; along with notable reduction in particle size and increase in zeta potential. Tertiary structural changes of the sonicated hydrolysates were illustrated by UV and fluorescence spectra. FTIR showed that ultrasonication increased α-helix, β-turn, and random coil by 38.23 %, 46.35 % and 16.36 %, respectively, but decreased β-sheet by 48.03 %, indicating partial unfolding in HLP hydrolysate conformation and reduction in intermolecular interactions. The research results demonstrated that dual-sweeping-frequency ultrasonication has a great prospect in industry application for the purpose of improving enzymolysis efficiency and product quality for housefly larvae protein hydrolysates production.

High concentration bioethanol production from corn stalk via enhanced pretreatment with ionic liquids

The transformation of lignocellulose into bioethanol is of great significance for energy security and environmental protection. Traditionally, the concentration of ethanol obtained by fermentation does not exceed 7 % (v/v), resulting in high cost of rectification (about 100 t water are needed to produce 1 t ethanol) and a large amount of wastewater, which is not suitable for industrial production. In this study, producting high concentration bioethanol from ionic liquid pretreated corn stalk integrated by feed-batch method was proposed. The cellulose content and the lignin removal rate of the corn stalk pretreated by [BHEM]mesy-ethylene glycol co-solvent system (rich-cellulose material) were 91 % and 93 %, respectively. The co-solvent system showed stable pretreatment efficiency after amplification of 20 times. Observably, the rich-cellulose material became easier to enzymolysis because the lower crystallinity from XRD, less lignin from CLSM and so on. The optimal enzymolysis conditions were 160 EGU/g cellulose, 50 ℃, pH = 4.8, 96 h, under which the yield of glucose could reach 90 %. The tolerance limit of Saccharomyces cerevisiae to glucose concentration is 0.3 g/L. The viscosity of enzymolysis materials was one of the main factors limiting the efficiency of enzymolysis by rheometer, and the 5 % concentration of materials was the most suitable for enzymolysis. Significantly, by feed-batch method, the glucose concentration reached 250 g/L with the yield of 100 %. The ethanol concentration is 93 g/L with the yield of 73 %. This study provided the possibility for industrialization of bioethanol production.

Effects of enzymatic treatments on different crystal types of starch

Porous starch is a denatured starch product with high porosity, a large specific surface area, and strong adsorption. It is widely used in medicine, food, and chemical industries. Native starch includes types A, B, and C. In this study, the various starch materials, including potato maize, and kudzu starch, were used to prepare different crystal types of porous starch with α-amylase and glucoamylase. The structural and chemical characteristics of the porous starch were measured using Fourier-transform infrared spectroscopy, scanning electron microscopy, X-ray diffraction, and differential scanning calorimetry. The results showed that maize , potato and kudzu starches were typically A, B, and C types, respectively. Compared to the native starch, the three types of porous starch treated with α-amylase and Glucoamylase cause varying degrees of destruction of the surface of the starch. Moreover, investigating the reaction factors which are expected to affect the water adsorption capacity were studied systematically, including the mass ratio of α-amylase to glucoamylase (m α-amylase/m glucoamylase), the mass ratio of the total amount of enzymes to starch (m enzyme/m St), enzymatic reaction temperature, and enzymatic reaction time. The results suggested that A-type starch has higher enzymolysis efficiency than other types of starch and can be used to produce ideal cavity and pore-size starch granules with potential applications in many fields.

Fabrication of Dual-Stimuli-Responsive Polymer Vesicles for Regulation of Enzymolysis Efficiency in A Cascade Reaction.

Enzymatic cascade reactions in confined microenvironments play important roles in cellular chemical transformation. Controlling enzymatic efficiency and eliminating substrate interference in cascade reactions is of great significance. To this end, a vesicle composed of poly(styrene-maleic anhydride-N-isopropylacrylamide)(P(S-M-NIP)) and functionalized with 1,2-bis(10,12- tricosadiynoyl)-sn-glycero-3-phosphocholine (DC89 PC) was designed herein. Based on the thermo-sensitive property of P(S-M-NIP) and the photo-responsive property of DC89 PC, a serial of dual-stimuli-responsive nanoreactors was constructed via enzymes encapsulation to tune their enzymolysis efficiencies. A kinetics study of the glucose oxidase-encapsulated nanoreactor indicated that its enzymolysis velocity increased 2.1- and 1.6-fold under heating and the ultraviolet (UV)-light irradiation, respectively. Consequently, an enzymatic cascade reaction in the proposed enzyme reactor encapsulated with β-galactosidase and glucose oxidase was investigated. The results revealed a 2.9-fold enhancement in enzymolysis efficiency by changing the ambient temperature under UV irradiation. The dual-stimuli-responsive polymer vesicles could also eliminate H2 O2 interference during the enzymatic cascade reaction. The vesicles demonstrated potential for switch-membrane-permeability, while, the confined microenvironment played a key role in regulating the reactions upon the temperature change and the presence of UV light. Our synthetic multi-organelle-like system provides a new way to mimic the control of cascade reaction catalytic processes by programming the "open/close" sates of the nanocapsules.

Selective degradation of hemicellulose and lignin for improving enzymolysis efficiency via pretreatment using deep eutectic solvents

Deep eutectic solvents (DESs) with different acidity and alkalinity were applied for biomass pretreatment, and the conditions were optimized by response surface methodology. The results showed that lactic acid/betaine hydrochloride had the optimal pretreatment efficiency, where the removal rates of hemicellulose and lignin came up to 89% and 73%, and the enzymolysis efficiency was as high as 92%. Furthermore, eight types of chloride salts with different valence states were introduced into the DESs as the third component. The chloride salts could improve the pretreatment efficiency and positively correlated with the metal valence state. Specifically, AlCl3 was significantly superior in improving the pretreatment efficiency, where the enzymolysis efficiency reached 96% due to the destruction of crystalline region and the esterification of partial cellulose. Therefore, it is proposed that adding highly valent metal salts to acidic DESs has higher pretreatment and enzymatic efficiency.

Thermo-responsive polymer-modified metal-organic frameworks as soft-rigid enzyme-reactors for enhancement of enzymolysis efficiency using a controllable embedding protocol.

Enzyme immobilization is a suitable strategy to promote biosensing, biocatalysis and the industrial applications of biomacromolecules. Although considerable efforts have been devoted to the construction of metal-organic frameworks (MOFs)-based porous nano-reactors, their enzymolysis efficiency cannot be tuned by varying the external conditions due to the fixed conformation of the encapsulated enzymes. In this work, a controllable embedding protocol was developed based on the concept of stimuli-responsive polymer modified MOFs. Using MOFs as a rigid template for thermo-responsive polymer modification and consequently utilizing the polymer-MOFs complexes for enzyme (glucose oxidase, horseradish peroxidase, trypsin, cytochrome c, glutaminase) immobilization, different porous nano-reactors were fabricated. Most importantly, the polymer on the MOF surface exhibited good ability to form a "soft nest" at high temperature for inducing the confinement effect and further improving the enzymolysis efficiencies of the nano-reactors 3.75-37.7-fold. Moreover, a colorimetric sensing method was developed to detect serum glucose with the proposed nano-reactors. This strategy is highly versatile and suitable for diverse rigid MOFs modified with stimuli-responsive soft-polymer-nests and enzymes.

In Situ Monitoring of Intracellular ATP Variation Based on a Thermoregulated Polymer Nanocomposite.

It is necessary to develop reliable chemiluminescence strategies for determination of intracellular adenosine triphosphate (ATP), which is vital in life science and clinical diagnosis. However, the current chemiluminescence methods based on firefly luciferase suffered from low delivery efficiency, unsatisfied targeting performance, and autohydrolysis in living biosystem. To circumvent these drawbacks, a thermoresponsive polymer nanocomposite modified with firefly luciferase and ATP aptamer (PFLNC@aptamer) was fabricated, which targeted ATP and determined the intracellular ATP levels via measuring the chemiluminescence signals at different temperatures. The PFLNC@aptamer exhibited capability for the enzymolysis efficiency regulation, increased 21.0% with temperature change from 37.0 to 25.0 °C. The ATP detection limit was 3.3 nM with a linear relationship from 10.0 nM to 0.1 mM. Moreover, the thermoresponsive nanocomposite could also effectively avoid the interference during delivering firefly luciferase into the living cells and effectively discriminate ATP via the immobilized ATP aptamer, which further confirmed its reliability for practical applications. It paves a specific avenue for effective intracellular ATP monitoring in fundamental and applied research.

Fabrication of Polymer Membrane Enzyme Reactors with a Dual-Responsive Feature for Cascade Enzyme Reaction Regulation.

Enzymes are known to drive biological processes efficiently and uniquely. However, the integration of multienzymes and immobilization technology to improve the stability of enzymes and boost the catalytic efficiency in cascade reactions by controlling the biocatalysis process in complex conditions via an external stimulus is still facing a significant challenge. Herein, we demonstrate a concept for cascade enzyme reaction regulation by controlling the catalytic efficiency step by step based on a dual-stimuli-responsive porous polymer membrane enzyme reactor (DPMER). Poly(styrene-maleicanhydride-acrylic acid-4-[(4-methacryloyloxy)phenylazo] benzoic acid) was designed for the fabrication of the DPMER with glutaminase and alanine aminotransferase as the model modified enzymes. Under UV light irradiation and by regulating the solution pH, the cascade enzyme reaction was carried out step by step. The polymer membrane surface demonstrated a configuration change while improving the enzymolysis efficiency of the DPMER. The enzymatic kinetics of the DPMER was investigated by a chiral capillary electrophoresis technique, and the cascade enzyme reaction regulation capability was evaluated. Under pH of 4.9 and 365 nm UV irradiation, the poly(4-[(4-methacryloyloxy)phenylazo] benzoic acid) and poly(acrylic acid) moieties changed from a "stretched state" to a "curled state" to form surface nanopores, which embedded the enzymes into the surface nanopores while causing the spatial confinement effect and enhancing the enzymolysis efficiency of the DPMER by 9.9-fold in comparison with the free enzymes. This concept provided a potential platform for cascade enzyme reaction regulation and highlighted the perspective of stimuli-responsive polymers.

Redox-Responsive Polymer Nanoreactors Based on Methionine Sulfoxide for Monitoring Cell Adhesion.

Expanding the category of redox-responsive monomers suitable for enzymolysis efficiency regulation and application to living biosystems is a prerequisite to complementing the fabrication of stimuli-responsive polymer nanoreactors. However, the development of redox-responsive monomers is severely limited by chemical oxidation and low biocompatibility. This work presents a protocol for overcoming this problem by the self-assembly of redox-responsive polymer nanoreactors containing segments of water-soluble methionine sulfoxide residues and poly(styrene-co-maleic anhydride-l-methionine), and by immobilizing α-l-fucosidase into the nanoreactors. These nanoreactors demonstrate highly selective responses to a mild redox triggered by H2O2 from the initial state (VO) to an oxidation state (VO1), and are reduced by methionine sulfoxide reductase A to mold the VO' state. It resulted in significantly enhanced enzymolysis efficiency and maximal reaction rates 8.1-fold (VO) and 23.3-fold (VO1) higher than those of the free enzyme. Moreover, cell adhesion was evaluated by the highly selective determination of l-fucose on cell surfaces. Using a combination of chemical oxidation and enzymatic reduction, this work achieves reiterative enzymolysis efficiency regulation of polymer nanoreactors, which has great potential for the construction of redox-responsive nanoreactors and for monitoring cell adhesion.

Biodegradation and hydrolysis of rice straw with corn steep liquor and urea-alkali pretreatment.

The current study evaluated the corn steep liquor (CSL) and urea-alkali pretreatment effect to enhance biodegradation and hydrolysis of rice straw (RS) by ruminal microbiome. The first used RS (1) without (Con) or with additives of (2) 4% CaO (Ca), (3) 2.5% urea plus 4% CaO (UCa) and (4) 9% corn steep liquor + 2.5% urea + 4% CaO (CUCa), and then the efficacy of CSL plus urea-alkali pretreatment was evaluated both in vitro and in vivo. The Scanning electron microscopy, X-ray diffraction analysis, cellulose degree of polymerization and Fourier-transform infrared spectroscopy, respectively, results showed that Ca, UCa, and CUCa pretreatment altered the physical and chemical structure of RS. CSL plus Urea-alkali pretreated enhanced microbial colonization by improving the enzymolysis efficiency of RS, and specially induced adhesion of Carnobacterium and Staphylococcus. The CUCa pretreatment could be developed to improve RS nutritional value as forage for ruminants, or as feedstock for biofuel production.

Improving the enzymolysis efficiency of lupin protein by ultrasound pretreatment: Effect on antihypertensive, antidiabetic and antioxidant activities of the hydrolysates

This study evaluated the impact of ultrasound pretreatment (UP) and enzyme type (flavourzyme, alcalase) on amino acid composition, antihypertensive, antidiabetic, and antioxidant activities of lupin protein hydrolysate (LPH). The UP altered molecular weight of the hydrolysates as revealed by SDS-PAGE and MALDI-TOF and their surface hydrophobicity and thermal stability. Amino acid analysis revealed that glutamic acid, aspartic acid, arginine, and leucine were the dominant amino acids lupin protein. Generally, sonicated hydrolysates exhibited higher biological activity than non-sonicated samples and the original LPI. Alcalase hydrolysate pretreated for 10 min showed the highest DPPH and metal chelating activities. Highest ACE inhibitory activity was observed in flavourzyme hydrolysate after 5 min of UP, while maximum α-amylase and glucosidase inhibitory activity was achieved after 10 min of UP in flavourzyme hydrolysate. The results obtained in this study demonstrated the potentials of UP as a valuable tool for enhancing the biological activity of lupin proteins.

Enzymolysis kinetics, thermodynamics and structural property of brewer’s spent grain protein pretreated with ultrasound

Enzymolysis kinetics, thermodynamics and molecular conformation of brewer’s spent grain protein (BSGP) pretreated with ultrasound were examined. Results showed that ultrasound pretreatment significantly reduced Michaelis constant (Km) and the thermodynamic parameters, including activation energy (Ea), enthalpy (ΔH), entropy (ΔS) and Gibbs free energy (ΔG) of BSGP during enzymolysis. Moreover, the initial reaction rate (Vi), association constant (Ka) and reaction rate constants (k) of BSGP pretreated with ultrasound were higher than those of native BSGP. The spectral analysis with Ultraviolet-visible (UV–vis) and Fourier transform infrared (FTIR) manifested that ultrasound pretreatment exposed hydrophobic groups and induced molecular unfolding of BSGP. Particle size analysis and scanning electron microscopy (SEM) showed that ultrasound pretreatment decreased particle size while increasing flexibility of BSGP. All these structural changes resulted in the improvement on enzymolysis efficiency of BSGP pretreated with ultrasound. Therefore, ultrasound pretreatment could be an efficient method to enhance the enzymolysis sensibility of BSGP.

Dual-stimuli-responsive porous polymer enzyme reactor for tuning enzymolysis efficiency.

Astrategy for preparing a dual-stimuli-responsive porous polymer membrane enzyme reactor (D-PPMER)is described, consisting of poly (styrene-maleic anhydride-N-isopropylacrylamide-acrylate-3',3'-dimethyl-6-nitro-spiro[2H-1-benzopyran-2,2'-indoline]-1'-esterspiropyran ester) [P(S-M-N-SP)] and D-amino acid oxidase. Tunable control via "on/off" 365nm UV light irradiation and temperature variation was used to change the membrane surface configuration and adjust the enzymolysis efficiency of the D-PPMER. A chiral capillary electrophoresis technique was developed for evaluation of the enzymatic efficiency of D-PPMER with a Zn(II)-dipeptide complex as the chiral selector and D,L-serine as the substrate. Interestingly, the enzymatic kinetic reaction rate of D-PPMER under UV irradiation at 36°C (9.2 × 10-2mM·min-1) was 3.2-fold greater than that of the free enzyme (2.9 × 10-2mM·min-1). This was because upon UV irradiation at high temperature, the P(SP) and P(N) moieties altered from a "stretched" to a "curled" state to encapsulate the enzyme in smaller cavities. The confinement effect of the cavities further improved the enzymatic efficiency of the D-PPMER. This protocol highlights the outstanding potential of smart polymers, enables tunablecontrol over the kinetic rates of stimuli-responsive enzyme reactors, and establishes a platform for adjusting enzymolysis efficiency using two different stimuli.

Properties, digestion and peptide release of heat-induced duck egg white

In this study, moisture content, textural properties, microstructure, free sulfhydryl group content, the secondary structure of heat-induced duck egg white gels (DEWG) under different heating temperatures of 80 °C, 90 °C, 100 °C and times of 10, 15, 20, and 25 min were investigated. Enzymolysis efficiency and peptide mapping were determined to clarify the linkage mechanism in gel properties, digestion behavior and peptide release of DEWG. Results indicated that with the increasing temperature and time, a gel with harder texture and less moisture was formed. Related gel exhibited a more compact form of aggregation in the environmental scanning electron microscopy (ESEM) and transmission electron microscope (TEM), as well as an increase in the amount of free sulfhydryl group and β-sheet. The in vitro digestibility and the number of peptides produced were affected by protein aggregation morphology. The gel with low induction temperature and shorter induction time showed a loose structure, resulting in a higher digestibility and more quantity of peptides released. In conclusion, heat induced changes in gelation behavior of duck egg white protein, and thus exhibited critical effects on protein digestion and peptide released.

Optimization of Enzymolysis Clearance Strategy To Enhance Renal Clearance of Radioligands.

The kidney is the main dose-limiting organ in radioligand therapy (RLT), and there is an urgent need for reducing renal radioactivity accumulation. According to the enzymolysis clearance strategy, the first objective of this study is to test whether enzymolysis efficiency can be improved by introducing a hydrophobic amino acid with a bulkier side chain to the second position of the cleavable sequence, and the second objective is to screen an optimal sequence to minimize the renal uptake. Four exendin 4 (Ex4) peptide analogues with different cleavable sequences were synthesized and labeled with 68Ga. Both in vitro and in vivo metabolism studies were performed using either the model compounds or the complete probes. The in vitro stabilities of the tracers were evaluated in PBS and mouse serum. The microPET images were acquired in the INS-1 tumor model at different time points, and the radioactivity uptakes of the probes in tumors and kidneys were determined and compared. All the probes were stable in both PBS and mouse serum for at least 1 h. The in vitro cleavage study for both model compounds and intact probes showed enzymolysis efficiency in the following order: MWK > MFK > MVK > MGK. The in vivo metabolism study confirmed that a fragment of 68Ga-NOTA-Met-OH appeared in both kidney and urine samples for all analogues with MVK, MFK, and MWK sequences. The microPET images showed that the tumor uptakes of all the modified probes were comparable to those of the control, while the kidney uptakes were significantly reduced by inserting the MWK, MFK, or MVK linker. The tumor-to-kidney ratios at 0.5, 1, and 2 h time points showed the following order: 68Ga-NOTA-MWK-Ex4 > 68Ga-NOTA-MFK-Ex4 > 68Ga-NOTA-MVK-Ex4. In this study, based on the enzymolysis clearance strategy and the preference of the enzyme, different sequences were designed and compared both in vitro and in vivo. The results indicated that the larger the steric hindrance of the second hydrophobic amino acid side chain, the more effective the enzymatic hydrolysis, with enzymolysis efficiency in the following order: MWK > MFK > MVK > MGK. MWK appears to be the most effective sequence in reducing renal radioactivity accumulation of exendin 4 peptide derivatives.

Design of Switchable Enzyme Carriers Based on Stimuli-Responsive Porous Polymer Membranes for Bioapplications.

Design of efficient enzyme carriers, where enzymes are conjugated to supports, has become an attractive research avenue. Immobilized enzymes are advantageous for practical applications because of their convenience in handling, ease of separation, and good reusability. However, the main challenge is that these traditional enzyme carriers are unable to regulate the enzymolysis efficiency or to protect the enzymes from proteolytic degradation, which restricts their effectiveness of enzymes in bioapplications. Enlightened by the stimuli-responsive channels in the natural cell membranes, conjugation of the enzymes within flat-sheet stimuli-responsive porous polymer membranes (SR-PPMs) as artificial cell membranes is an efficient strategy for circumventing this challenge. Controlled by the external stimuli, the multifunctional polymer chains, which are incorporated within the membranes and attached to the enzyme, change their structures to defend the enzyme from the external environmental disturbances and degradation by proteinases. Specifically, smart SR-PPM enzyme carriers (SR-PPMECs) not only permit convective substrate transfer through the accessible porous network, dramatically improving enzymolysis efficiency due to the adjustable pore sizes and the confinement effect, but they also act as molecular switches for regulating its permeability and selectivity. In this review, the concept of SR-PPMECs is presented. It covers the latest developments in design strategies of flat-sheet SR-PPFMs, fabrication protocols of SR-PPFMECs, strategies for the regulation of enzymolysis efficiency, and their cutting-edge bioapplications.

Enzyme immobilization on a pH-responsive porous polymer membrane for enzymatic kinetics study

Immobilization of enzymes onto carriers is a rapidly growing research area aimed at increasing the stability, reusability and enzymolysis efficiency of free enzymes. In this work, the role of phase-separation and a pH-responsive “hairy” brush, which greatly affected the topography of porous polymer membrane enzyme reactors (PMER), was explored. The porous polymer membrane was fabricated by phase-separation of poly(styrene-co-maleic anhydride-acrylic acid) and poly(styrene-ethylene glycol). Notably, the topography and pores size of the PMER could be controlled by phase-separation and a pH-responsive “hairy” brush. For evaluating the enzymolysis efficiency of d-amino acid oxidase (DAAO) immobilized carrier (DAAO@PMER), a chiral ligand exchange capillary electrophoresis method was developed with d-methionine as the substrate. The DAAO@PMER showed good reusability and stability after five continuous runs. Notably, comparing with free DAAO in solution, the DAAO@PMER exhibited a 17.7-folds increase in catalytic velocity, which was attributed to its tailorable topography and pH-responsive property. The poly(acrylic acid) moiety of poly(styrene-co-maleic anhydride-acrylic acid) as the pH-responsive “hairy” brush generated topography changing domains upon adjusting the buffer pH, which enable the enzymolysis efficiency of DAAO@PMER to be tuned based upon the well-defined architectures of the PMER. This approach demonstrated that the topographical changes formed by phase-separation and the pH-responsive “hairy” brush indeed made the proposed porous polymer membrane as suitable supports for enzyme immobilization and fitting for enzymolysis applications, achieving high catalytic performance.

Enhanced enzymatic hydrolysis and hydrogen production of sugarcane bagasse pretreated by peroxyformic acid

Pretreatment plays a key role in biofuel production from lignocellulosic biomass. In this study, the main factors of peroxyformic acid (PA) pretreatment were optimized in the light of enzymolysis efficiency and composition analysis of pretreated sugarcane bagasse (SCB). Lignin was significantly removed (59.0%) and a complete saccharification level (103.6%) was obtained for the pretreated SCB with slight cellulose loss (9.2%) under the optimized pretreatment conditions. The effects of PA pretreatment on the structural characteristics of SCB were also studied and the digestibility of pretreated SCB was also evaluated by dark fermentative hydrogen production with an enriched anaerobic cellulolytic microbial consortium MC1. The hydrogen production increased by 195.5% (based on initial SCB) and the abundance of dominant hemicellulose-degradation genus Thermoanaerobacterium increased from 23.8% to 40.2% due to the remaining and accessible hemicellulose in PA pretreated SCB.

Improvement in enzymolysis efficiency and bioavailability of rapeseed meal protein concentrate by sequential dual frequency ultrasound pretreatment

In order to improve the bioavailability of rapeseed meal protein concentrate (RPC), sequential dual frequency (50/28 kHz) ultrasound was applied to pretreat RPC and its protein bioavailability was investigated by in-vivo nitrogen-balance trials. Based on Box-Behnken experimental design, a set of preferred ultrasound pretreatment condition was determined to be at power density of 65.6 W/L for 38.6 min with an incubation temperature of 39.0 °C. Under these conditions, degree of hydrolysis and protein conversion rate of RPC respectively increased by 26.6 % and 32.9 % compared to the control. Meanwhile, the macromolecular protein of sonicated RPC was converted into more small molecular peptides with a molecular weight of 200∼1000 Da by enzymolysis, accompanied by the changes of amino acid composition in supernatant. Furthermore, the rats fed with hydrolysates (including supernatant and precipitate) derived from ultrasound pretreatment coupled with enzymolysis rather than traditional enzymolysis showed higher weight gain, protein efficiency ratio, net protein ratio, apparent digestibility and true digestibility. These findings revealed that ultrasound could be considered as a promising pretreatment technology for preparing enzymatic hydrolysates with high bioavailability and thus realize the maximum utilization of rapeseed meal protein.

Thermoresponsive Porous Polymer Membrane as a Switchable Enzyme Reactor for d-Amino Acid Oxidase Kinetics Study

Tuning the efficiency of enzymolysis in different environments is a challenge with important implications for the use of immobilized enzymes in biochemistry, pharmacology, and life science. Here, w...