Changes Of Trypsin Research Articles

Spectroscopic investigation and molecular docking analysis of an FRET probe: Trypsin from bovine pancreas@Coumarin 440 dye conjugate

Herein, a systematic investigation of energy transfer from bovine pancreas trypsin to coumarin 440 (C440) dye is presented with an aim to design a FRET probe, as trypsin is an important enzyme for absorption and digestion of nutrients in the small intestine. Conformational changes in trypsin upon interaction with C440 dye are studied by employing both spectroscopic and molecular docking techniques. Steady state and time resolved measurements validate the formation of trypsin-C440 complex via dynamic quenching, that confirms the role of C440 as an inhibitor to suppress the activity of trypsin. Spectral overlap integral, Förster's distance, rate and energy transfer efficiency are calculated from steady state measurements. The observed blue shift in fluorescence suggests conformational changes due to hydrophobicity that arises in trypsin structure on binding with C440 possibly due to their interaction through H-bond (SER195 and GLN192), hydrophobic (GLN192 and HIS57) and π-π stacking bonding (HIS57). The stability of trypsin@C440 bio-conjugate at higher temperature was established from temperature dependent PL studies and the thermodynamic parameters determined agree with second law of thermodynamics. The thermodynamic parameters such as change in enthalpy (ΔH=172.2Jmol−1), change in entropy (ΔS=15.3Jmol−1K−1) and the respective approximately same and unity values of Gibb's free energy (ΔG) and Hill coefficient (n), as well as binding affinities determined from temperature dependent fluorescence studies validate the hydrophobic, spontaneous, exothermic process engaged in trypsin@C440 bio-conjugate.

Characterization of the interactions between Fulvic acid and Trypsin with Spectroscopic and Molecular Docking technology.

The interaction mechanism between trypsin and fulvic acid was analyzed by multispectral method and molecular docking simulation. The fluorescence spectra showed that fulvic acid induced static quenching of trypsin. The validity of this conclusion was further substantiated through the computation of the binding constants. The thermodynamic parameters show that the reaction is mainly controlled by van der Waals force and hydrogen bond force, and the reaction is spontaneous. In addition, based on the obtained binding distance, there may be a non-radiative energy transfer between the two. The ultraviolet spectrum showed that fulvic acid could shift the absorption peak of trypsin, indicating that fulvic acid had an effect on the secondary structure of trypsin. According to the synchronous fluorescence spectrum results, fulvic acid primarily interacts with tryptophan residues in trypsin and induces alterations in their microenvironment. Three-dimensional fluorescence spectrum and circular dichroism further proves this conclusion. The molecular docking simulation reveals that the interaction between the two groups primarily arises from hydrogen bonding and van der Waals forces. The findings suggest that FA has the ability to induce conformational changes in trypsin's secondary structure.

Bimetallic oxide Mg-Cu nanoparticles synthesis and application in photometric sensing of trypsin in the presence of tap water, ammonia, and glutamine

The concentration of biomolecules such as trypsin and ammonia in bodily fluids are indicators of health conditions including pancreatic diseases and acute liver failure respectively. The maximum UV-Visible intensity and wavelength shifts of Mg-Cu bimetallic oxide nanoparticles (BNPs) were found to be proportional to changes in trypsin and ammonia concentration. The BNPs could selectively detect trypsin in tap water containing ions, ammonia, and glutamine at concentrations as low as 0.0003%v/v. The synthesis of Mg-Cu BNPs was accomplished by ablating a mixture of Mg and Cu powders and Mg and Cu colloids using a Nd:YAG 1064 nm laser in isopropanol alcohol and HCl. The BNPs demonstrated higher optical absorbance intensity in the UV-Visible range compared to their monometallic constituents, making them more suitable for use in biochemical sensing of trypsin and ammonia. The BNPs exhibited a massive 730-fold increase in electrical conductivity compared to monometallic Mg nanoparticles (0.001 mS/cm vs. 0.73 mS/cm). Field emission scanning electron microscopy was used to visualize the NP morphologies, revealing pyramidal and quasi-spherical BNPs with diameters as small as 5 nm.

Conformational dynamics of trypsin in the presence of caffeic acid: a spectroscopic and computational investigation

Caffeic acid is one of the widely distributed phenolic compounds in nature and can be found in planet products. On the other hand, trypsin is a vital digestive enzyme in the intestine that plays an essential role in the immune response, blood coagulation, apoptosis and protein maturation like protein digestion. Several studies have revealed the inhibitory effects of the phenolic compound on the digestive enzyme. The present study reports functional and conformational alteration of trypsin after caffeic acid addition using multiple experimental and computational techniques for the first time. The intrinsic fluorescence of trypsin is quenched in the presence of caffeic acid via a static mechanism. The percent of secondary structures (α-helix and β-sheet) of trypsin alter after caffeic acid addition. In the kinetic study, a reduction in the trypsin function is obtained with a lower V max and K cat upon interaction with caffeic acid. The thermal study reveals an unstable structure of trypsin upon complex formation with this phenolic compound. Also, the binding sites and conformational changes of trypsin are elucidated through molecular docking and molecular dynamic simulation. Communicated by Ramaswamy H. Sarma

Characterization of endogenous enzymes in sword prawn (Parapenaeopsis hardwickii) and their effects on the quality of muscle proteins during frozen storage

Muscle deterioration caused by endogenous enzymes can greatly impact the quality of shrimp products during their processing and storage. In this study, the changes in trypsin, calpain, and cathepsin activity and their effects on muscle proteins in the intact and beheaded shrimp during 120 days of frozen storage were investigated. The results showed that the hardness, stretching force, chewiness, myofibrillar protein (MP) content, and Ca2+-ATPase activity significantly decreased in both the intact and beheaded shrimp samples with the prolonged storage period. Notably, the beheaded shrimp exhibited more stable characteristics than the intact shrimp samples throughout frozen storage. The endogenous enzyme analysis showed that the variations in the trypsin, calpain, and cathepsin activities were significantly pronounced in the intact shrimp compared to those in the beheaded samples. Furthermore, the myofibrillar fragmentation index, SDS-PAGE, and histological structure analysis revealed that the beheading treatment on the shrimp greatly inhibited the dissociation of muscle proteins during frozen storage. Our findings showed that the trypsin in the head of shrimp could be transferred to muscle tissues through the first abdominal segment during long-term storage, thus accelerating the degradation of MPs in the muscle tissues. Therefore, the beheading treatments effectively prolonged the shelf-life of stored shrimp products.

Association Mechanism and Conformational Changes in Trypsin on Its Interaction with Atrazine: A Multi- Spectroscopic and Biochemical Study with Computational Approach.

Atrazine (ATR) is a herbicide globally used to eliminate undesired weeds. Herbicide usage leads to various adverse effects on human health and the environment. The primary source of herbicides in humans is the food laced with the herbicides. The ATR binding to trypsin (TYP) was investigated in this study to explore its binding potential and toxicity. In vitro interaction of ATR with TYP was studied using multi-spectroscopic methods, molecular docking, and enzyme kinetics to explore the mechanism of binding for the TYP-ATR system. The TYP-ATR complex revealed binding constants (103 M−1), suggesting a moderate binding. The free energy for the TYP-ATR complexes was negative, suggesting a spontaneous interaction. Thermodynamic parameters enthalpy (ΔH) and entropy (ΔS) obtained positive values for the TYP-ATR system suggesting hydrophobic interactions in the binding process. Micro-environmental and conformational changes in TYP molecules were induced on interaction with ATR. Reduced catalytic activity of TYP was observed after interaction with ATR owing to the changes in the secondary structure of the TYP.

Metabolic Energy Insufficiency in Mice Kidney following Short-term Exposure to Lead: An In-vivo Study

Background: Metabolic stress is one of the risk factors of lead-induced functional abnormalities of the tissue. The present study aimsat determining the effect of lead on certain energy metabolic profiles in renal tissue of mice.Method: Swiss albino mice were exposed to Pb by gavages at a 5mg/kg body weight dose for 30 days. After treatment, urinary glucose,glucose 6-phosphatase, lactate dehydrogenase, TCA cycle enzymes, different proteolytic enzyme activities, total, acidic, basic and neutralproteins, protein carbonyl content, glyceraldehyde 3-phosphate dehydrogenase activity, tissue Pb deposition and renal morphologywere examined.Results: Lead exposure resulted in glycosuria and decreased glucose 6-phosphatase activity in the kidney, whereas the lactatedehydrogenase activity was increased in that tissue. The malate dehydrogenase and succinate dehydrogenase activities were stimulatedby Pb, whereas the glyceraldehyde 3-phosphate dehydrogenase activity was inhibited. Degradation of tissue protein was accompaniedwith enhanced protein carbonylation. Significant changes in trypsin, cathepsin and pronase activities were noted. Decreased aminoacid nitrogen in kidney was associated with altered transaminase activity. Additionally, fatty infiltration was observed in associationwith accumulation of elemental lead.Conclusion: It is suggested that sub-acute Pb exposure modulated certain enzymes and intermediates of major energy metabolismpathways in the renal tissue of mice to establish an adaptive mechanism against metabolic distress.

A Study of the Interaction, Morphology, and Structure in Trypsin-Epigallocatechin-3-Gallate Complexes.

Understanding the interaction between proteins and polyphenols is of significance to food industries. The aim of this research was to investigate the mode of aggregation for trypsin-EGCG (Epigallocatechin-3-gallate) complexes. For this, the complex was characterized by fluorescence spectroscopy, circular dichroism (CD) spectra, small-angel X-ray scattering (SAXS), and atomic force microscope (AFM) techniques. The results showed that the fluorescence intensity of trypsin-EGCG complexes decreased with increasing the concentration of EGCG, indicating that the interaction between trypsin and EGCG resulted in changes in the microenvironment around fluorescent amino acid residues. The results of CD analysis showed conformational changes in trypsin after binding with EGCG. The results from SAXS analysis showed that the addition of EGCG results in the formation of aggregates of trypsin-EGCG complexes, and increasing the concentration of EGCG resulted in larger aggregates. AFM images showed that the trypsin-EGCG complex formed aggregates of irregular ellipsoidal shapes with the size of about 200 × 400 × 200 nm, with EGCG interconnecting the trypsin particles. Overall, according to these results, it was concluded that the large aggregates of trypsin-EGCG complexes are formed from several small aggregates that are interconnected. The results of this study shed some light on the interaction between digestive enzymes and EGCG.

Exploring the interactions of naringenin and naringin with trypsin and pepsin: Experimental and computational modeling approaches

Naringenin and naringin are two natural compounds with important health benefits, whether as food or drug. It is necessary to study the interactions between naringenin/naringin and digestive proteases, such as trypsin and pepsin. In this study, the bindings of naringenin and naringin to trypsin and pepsin were investigated using multi-spectroscopy analysis and computational modeling approaches. Fluorescence experiments indicate that both naringenin and naringin can quench the intrinsic fluorescence of trypsin/pepsin via static quenching mechanism. Naringin binds trypsin/pepsin in a more firmly way than naringenin. Thermodynamic analysis reveals that the interactions of naringenin/naringin and trypsin/pepsin are synergistically driven by enthalpy and entropy, and the major driving forces are hydrophobic, electrostatic interactions and hydrogen bonding. Synchronous fluorescence spectroscopy, circular dichroism spectroscopy and FT-IR show that naringenin/naringin may induce microenvironmental and conformational changes of trypsin and pepsin. Molecular docking reveals that naringenin binds in the close vicinity of the active site (Ser-195) of trypsin and Asp-32 (the catalytic activity of pepsin) appears in naringin-pepsin system. The direct interactions between naringenin or naringin and catalytic amino acid residues will inhibit the catalytic activity of trypsin and pepsin, respectively. The results of molecular dynamic simulation validate the reliability of the docking results.

Structural changes in trypsin induced by the bile salts: An effect of amphiphile hydrophobicity

The present study reports the multi-technique results of the interaction of a series of bile salts, sodium cholate (NaC), sodium taurocholate (NaTC), sodium deoxycholate (NaDC), and sodium taurodeoxycholate (NaTDC) with trypsin under the experimental conditions of 25 °C and pH 7.0. The interactions between trypsin and the bile salts were characterized by the surface tension measurements and various spectroscopic techniques like UV–Visible absorption, steady-state fluorescence, and circular dichroism. The results of surface tension measurements reveal a strong interaction of trypsin (50 μM) with the increasing concentration of bile salts, being higher with the bile salt of greater hydrophobicity. The critical aggregation concentration of bile salts in the presence of trypsin (C1) showed that the bile salts interact strongly with the trypsin in the order of NaTDC > NaDC > NaTC > NaC. UV–visible, steady-state fluorescence, and circular dichroism spectroscopic results confirmed significant unfolding of trypsin due to its interaction with the bile salts, the extent of which followed the same sequence as observed in the surface tension results. It could be concluded that the hydrophobic bile salts that show lower C1 values and have less delocalized charge, are more effective in unfolding the trypsin. The study would help understand the hydrophobicity-driven unfolding of proteins aided by biological surfactants like bile salts and help devise efficient proteolytic enzyme-based detergent formulations and understand the role of such amphiphiles as antimicrobial agents.

Tryptophan Fluorescence and Time-Lag Hydrolysis of Peptide Bonds during Degradation of β-Lactoglobulin by Trypsin

The opening of protein globules and corresponding exposure of their internal peptide bonds, the so-called demasking effect, is required for successful hydrolysis of peptide bonds by proteases. Under the proteolytic action of trypsin on β-lactoglobulin (β-LG), the evolution of tryptophan fluorescence spectra showed that the demasking process consists of two stages with different demasking rate constants for each stage. It was found that the ratio of these constants depends on the concentration of trypsin and changes are approximately threefold when the concentration of trypsin changes in the range of 0.3–15 mg/L. Simulation of hydrolysis taking into account the demasking effect demonstrated how the apparent first-order rate constants obtained experimentally are related to the true hydrolysis rate constants and demasking parameters. The lag phase in the kinetic curves corresponding to the hydrolysis of various peptide bonds in β-LG was also analyzed. The increased lag times indicated sites that are hydrolyzed by a two-stage demasking mechanism.

Characterization on the toxic mechanism of two fluoroquinolones to trypsin by spectroscopic and computational methods

Ciprofloxacin (CPFX) and enrofloxacin (ENFX), two of the most widely used fluoroquinolones (FQs), pose a great threat to humans and the ecosystem. In this study, the toxic mechanisms between the two FQs and trypsin were evaluated by means of multiple spectroscopic methods, as well as molecular docking. During the fluorescence investigations, both FQs quenched the intrinsic fluorescence of trypsin effectively, which was due to the formation of moderately strong complexes (mainly through van der Waals forces and hydrogen bonds). The binding of two FQs not only caused the conformational and micro-environmental changes of trypsin, but also changed its molecular activity; shown by the UV–Visible absorption spectroscopy, synchronous fluorescence spectroscopy, and functional tests. The established methods in this work can help to comprehensively understand the transport of FQs in the human body.

Dissection of binding of trypsin to its natural inhibitor Gensenoside-Rg1 using spectroscopic methods and molecular modeling

The interaction of trypsin with Gensenoside-Rg1 (G-Rg1) was studied using fluorescence, ultraviolet–visible (UV–vis), and circular dichroism (CD) spectroscopies along with enzyme activity assay and molecular docking. The enzyme activity assays showed that G-Rg1 inhibited the activity of trypsin effectively. The fluorescence experiments indicated that a complex of G-Rg1–trypsin was formed and that the fluorescence of trypsin was quenched by G-Rg1 via a mixed-quenching mechanism (both static and dynamic quenching). The thermodynamic analysis suggested that hydrophobic interaction and hydrogen bond were the major forces between G-Rg1 and trypsin. According to the theory of Förster’s non-radiation energy transfer, the binding distance between trypsin and G-Rg1 was calculated to be 2.01 nm, which implies that energy transfer occurred within the complex. The experimental results obtained from UV–vis absorption spectra, synchronous fluorescence spectra, and CD spectra indicated that G-Rg1 was mainly located on tryptophan moiety and that the interaction between G-Rg1 and trypsin led to conformational changes of trypsin with some α-helix and unordered coil structures being transformed into β-sheet structures. In addition, docking results supported the above experimental findings and suggested the possible binding location of G-Rg1 on trypsin along with the possible hydrogen bonds and hydrophobic interactions between G-Rg1 and trypsin. The experimental results from this study should be useful to minimize the antinutritional effects and make full use of Genseng extracts in the food industry and also be helpful to the design of the drugs for the diseases related to overexpression of trypsin.Communicated by Ramaswamy H. Sarma

Probing the interaction of doxycycline to trypsin and bovine hemoglobin by using multi-spectral techniques and molecular docking

The interactions of doxycycline (DC) with digestive enzyme (trypsin) and intracellular protein (bovine hemoglobin, BHb) were investigated by using multi-spectral techniques and molecular docking. Fluorescence studies suggested that DC quenched trypsin fluorescence in a static quenching and BHb fluorescence in a combined quenching (dynamic and static quenching) with binding constants of 0.22 and 1.45×104L⋅mol−1 at 298K, respectively. The thermodynamic parameters demonstrated that the main forces of BHb-DC and trypsin-DC systems were hydrophobic forces, hydrogen bonds and van der Waals forces in the binding processes. Based on the results of FRET, the binding distances between DC and the inner tryptophan residues of trypsin and BHb were calculated to be 4.09 and 3.86nm, respectively. Furthermore, the results of circular dichroism spectra (CD) indicated the secondary structures of trypsin and BHb were partially changed by DC with the α-helix percentage of trypsin-DC system increased (6.3%–7.3%) and that of BHb-DC system also increased (38.5%–46.2%), the β-sheet percentage of trypsin-DC system decreased from 43.3% to 41.0%. UV–vis and three-dimensional fluorescence spectra results showed these binding interactions could cause conformational and some micro-environmental changes of trypsin and BHb. With the results of molecular docking, for trypsin, DC can bind to the active sites residues HIS 57 and SER 195 in the pocket of trypsin, thereby increasing the activity of trypsin, for BHb, DC binds into the hydrophobic cavity of BHb via multiple interactions. The work contributes to understand the interactions of DC with trypsin/BHb at molecular level.

Mechanism and Nature of Inhibition of Trypsin by Ligupurpuroside A, a Ku-Ding Tea Extract, Studied by Spectroscopic and Docking Methods

Ligupurpuroside A is a glycoside extracted from Ku-Ding tea. As extracts from Ku-Ding tea exhibit anti-inflammatory property, we hypothesize that Ligupurpuroside A may be an active compound which inhibits trypsin activity during the anti-inflammatory process. The mechanism and nature of inhibition of trypsin by Ligupurpuroside A have been studied by multi-spectroscopic method, enzyme-activity assay and molecular docking. Enzyme activity assay reveals that Ligupurpuroside A significantly inhibits the activity of trypsin through a competitive manner with an IC50 value of 3.08 × 10−3 mol L−1. Fluorescence titration together with thermodynamic analysis indicate that a Ligupurpuroside A-trypsin complex is formed, and that hydrophobic force and hydrogen bonding are the main forces stabilizing the complex. UV-vis absorption, synchronous fluorescence and circular dichroism spectra show that the interaction between Ligupurpuroside A and trypsin induces conformational changes of trypsin with a decrease in the contents of α-helix and β-sheet. Finally, molecular docking further suggests that Ligupurpuroside A molecule binds within the active pocket of trypsin via hydrophobic force and hydrogen bond. Results from this study of the interaction of trypsin with its natural inhibitor should be useful to minimize the antinutritional effects and make full use of tea extracts in the food industry, and be also helpful to the design of the drugs for the diseases related to overexpression of trypsin.

A spectroscopic and thermal stability study on the interaction between putrescine and bovine trypsin

The interaction of putrescine with bovine trypsin was investigated using steady state thermal stability, intrinsic fluorescence, UV–vis spectroscopy, far and near- UV circular dichroism and kinetic techniques, as well as molecular docking. The Stern-Volmer quenching constants for the trypsin- putrescine complex were calculated revealing that putrescine interacted with trypsin via the static fluorescence quenching. The enthalpy and entropy change values and the molecular docking technique revealed that hydrogen bonds and van der Waals forces play a major role in the binding process. Upon putrescine conjugation, the Vmax value and the kcat/Km values of the enzyme was increased. The results of UV absorbance, circular dichroism and fluorescence techniques demonstrated that the micro environmental changes in trypsin were induced by the binding of putrescine, leading to changes in its secondary structure. The thermal stability of trypsin- putrescine complex was enhanced more significantly, as compared to that of the native trypsin. The increased thermal stability of trypsin- putrescine complex might be due to the lower surface hydrophobicity and the higher hydrogen bond formation after putrescine modification, as reflected in the increase of UV absorbance and the quenching of fluorescence spectra. It was concluded that the binding of putrescine changed trypsin structure and function.

Interaction between 8-methoxypsoralen and trypsin: Monitoring by spectroscopic, chemometrics and molecular docking approaches

8-Methoxypsoralen (8-MOP) is a naturally occurring furanocoumarin with various biological activities. However, there is little information on the binding mechanism of 8-MOP with trypsin. Here, the interaction between 8-MOP and trypsin in vitro was determined by multi-spectroscopic methods combined with the multivariate curve resolution-alternating least squares (MCR–ALS) chemometrics approach. An expanded UV–vis spectral data matrix was analysed by MCR–ALS, the concentration profiles and pure spectra for the three reaction species (trypsin, 8-MOP and 8-MOP–trypsin) were obtained to monitor the interaction between 8-MOP and trypsin. The fluorescence data suggested that a static type of quenching mechanism occurred in the binding of 8-MOP to trypsin. Hydrophobic interaction dominated the formation of the 8-MOP–trypsin complex on account of the positive enthalpy and entropy changes, and trypsin had one high affinity binding site for 8-MOP with a binding constant of 3.81×104Lmol−1 at 298K. Analysis of three dimensional fluorescence, UV–vis absorption and circular dichroism spectra indicated that the addition of 8-MOP induced the rearrangement of the polypeptides carbonyl hydrogen-bonding network and the conformational changes in trypsin. The molecular docking predicted that 8-MOP interacted with the catalytic residues His57, Asp102 and Ser195 in trypsin. The binding patterns and trypsin conformational changes may result in the inhibition of trypsin activity. This study has provided insights into the binding mechanism of 8-MOP with trypsin.

Probing the binding of procyanidin B3 to trypsin and pepsin: A multi-technique approach

Proanthocyanidins are a mixture of monomers, oligomers, and polymers of flavan-3-ols that are widely distributed in the plant kingdom. One of the most widely studied proanthocyanidins is procyanidin B3. In this study, the binding of procyanidin B3 to trypsin and pepsin was investigated using spectrofluorimetry, equilibrium microdialysis, circular dichroism (CD) spectroscopy and molecular modeling. Fluorescence experiments indicate procyanidin B3 quenches the fluorescence of trypsin/pepsin through a static process. Thermodynamic analysis reveals that procyanidin B3 binds to trypsin/pepsin is synergistically driven by enthalpy and entropy, and the major driving forces are hydrophobic, hydrogen bonding, and electrostatic interactions. Procyanidin B3 binds trypsin in a more firmly way than pepsin, and one molecule of procyanidin B3 combines with one molecule of trypsin/pepsin. The binding parameters obtained from equilibrium microdialysis are consistent with the results obtained from fluorescence spectroscopy. Synchronous fluorescence spectroscopy and CD spectroscopy show that procyanidin B3 may induce microenvironmental and conformational changes of trypsin and pepsin. Molecular modeling displays the specific binding site of procyanidin B3 on trypsin and pepsin. The study provides an accurate and full basic data for clarifying the binding mechanisms of procyanidin B3 with trypsin and pepsin and is helpful for understanding its biological activity in vivo.

New Insights into the Toxicity of n-Butanol to Trypsin: Spectroscopic and Molecular Docking Descriptions.

n-Butanol has been widely used and its residue exists extensively in the environment. It could lead to conformational and functional changes of trypsin by forming a complex with it. Docking method and spectrographic technique were employed to the study of the complex of trypsin and n-butanol. The fluorescence results indicated that n-butanol can form a complex with trypsin and change the distance between tryptophan and fluorescence quenchers. The conformational changes of trypsin were proved by UV-visible absorption and synchronous fluorescence spectroscopy indicating that n-butanol had little effect on the conformation of trypsin at a low concentration while denatured and coagulated the trypsin at a high concentration. The binding site was displayed by molecular modeling, which gave information about distances and binding forces between n-butanol and trypsin. The results were in accordance with spectroscopic experiments. Besides, enzyme activity assay gave the dose-response relationship of n-butanol with trypsin.

Potential toxicity of phthalic acid esters plasticizer: interaction of dimethyl phthalate with trypsin in vitro.

Dimethyl phthalate (DMP) is widely used as a plasticizer in industrial processes and has been reported to possess potential toxicity to the human body. In this study, the interaction between DMP and trypsin in vitro was investigated. The results of fluorescence, UV–vis, circular dichroism, and Fourier transform infrared spectra along with cyclic voltammetric measurements indicated that the remarkable fluorescence quenching and conformational changes of trypsin resulted from the formation of a DMP–trypsin complex, which was driven mainly by hydrophobic interactions. The molecular docking and trypsin activity assay showed that DMP primarily interacted with the catalytic triad of trypsin and led to the inhibition of trypsin activity. The dimensions of the individual trypsin molecules were found to become larger after binding with DMP by atomic force microscopy imaging. This study offers a comprehensive picture of DMP–trypsin interaction, which is expected to provide insights into the toxicological effect of DMP.