Sodium Dodecyl Sulfate Concentration Research Articles

Controlled Release of Drug-Encapsulated Protein Films with Various Sodium Dodecyl Sulfate Concentrations.

Protein-based drug carriers are ideal drug-delivery platforms because of their biocompatibility, biodegradability, and low toxicity. Many types and shapes of protein-based platforms, including nanoparticles, hydrogels, films, and minipellets, have been prepared to deliver drug molecules. In this study, protein films containing the desired amounts of doxorubicin (DOX) as cancer drugs were developed using a simple mixing method. The release ratio and rate of DOXs were dependent on the surfactant concentration. The drug release ratio was controlled within the range of 20-90% depending on the amount of the surfactant used. The protein film surface was analyzed using a microscope before and after drug release, and the relationship between the degree of film swelling and the drug release ratio was discussed. Moreover, the effects of cationic surfactants on the protein film were investigated. Non-toxic conditions of the protein films were confirmed in normal cells, while the toxicity of the drug-encapsulated protein film was confirmed in cancer cells. Remarkably, it was observed that the drug-encapsulated protein film could eliminate 10-70% of cancer cells, with the extent of efficacy varying based on the surfactant amount.

Determination of Critical Micelle Concentration of Sodium Dodecyl Sulfate in Distilled Water at 298.15K by Surface Tension Measurements

Surfactants are chemicals that adsorb to the interface between a solution and another phase (gases or solids) and self-assemble molecular clusters known as micelles in a solution (water or oil phase). Measurements of the surface tension of sodium dodecyl sulfate (SDS) in distilled water at 298.15K are reported. The increase of concentration of sodium dodecyl sulfate (SDS) in distilled water then decreased in surface tension at 298.15K. Critical micelle concentration (CMC) decreased with a decrease in surface tension. The graphs of surface tension versus concentration were made to determine the CMC of the solution.

Eco-friendly micellar HPLC approach for assessment of two anti-asthmatic breezhalers; Application of central composite design

Short-term breathing problems are brought on by asthma, a chronic lung disease. Mometasone furoate (MOF) and Indacaterol (IDT), are co-formulated alone or with Glycopyrronium (GLY) in the form of inhalation powder to control the symptoms of asthma. A novel green hybrid micellar liquid chromatographic method was developed to analyze the three mentioned medications. Contrary to routine analysis, Quality by Design methodology was applied to maximize the resolution with the fewest number of trials. Fractional factorial design was used to study the impact of three significant variables: sodium dodecyl sulphate (SDS) concentration, methanol %, and the mobile phase pH. Separation of the analytes was optimized by central composite design using a mobile phase consists of (191.49 mM) SDS and (10.00 mM) potassium dihydrogen phosphate buffer: methanol (77.50: 22.50 v/v), pH 3.00 on a reversed phase C18 column, within eight minutes. The flow rate was 1.2 mL/min, with 20 µL injection volume, and UV detection at 210 nm. Green Analytical Procedure Index, and Analytical Greenness Calculator were used for the method’s greenness evaluation, and it was deemed to be an effective green methodology. The developed approach was effectively applied for quantitative determination of the three drugs in bulk powder and two pharmaceutical dosage forms. International Conference of Harmonization requirements were adhered to when validating the approach. Under optimized conditions, calibration curves of the studied drugs were linear over the concentration range of (10.00 – 100.00 µg/mL) with high accuracy results and correlation coefficients of 0.9997 for MOF, 0.9996 for IDT and 0.9996 for GLY. Additionally, a precise approach has been demonstrated by the intra- and inter-day coefficients of variation ≤ 2%. The LOD and LOQ were (2.39 μg/mL) and (7.25 μg/mL) for MOF, (2.67 μg/mL) and (8.08 μg/mL) for IDT, and (2.80 μg/mL) and (8.48 μg/mL) for GLY, respectively.

A method to determine two antibiotics prescribed to treat nosocomial infections in plasma and urine by micellar liquid chromatography

Combined prescription of the antimicrobial drugs linezolid and meropenem is a common strategy to treat multidrug-resistant nosocomial infections. We propose an innovative method to determine these two drugs in plasma and urine, based on micellar liquid chromatography. Both biological fluids were diluted in mobile phase, filtered and directly injected, without any extraction step. Using a C18 column and a mobile phase of 0.1 M sodium dodecyl sulfate – 10 % methanol, phosphate buffered at pH 3, running under isocratic mode, both antibiotics were eluted without overlapping in<15 min. Detection was by absorbance: 255 nm for linezolid and 310 nm for meropenem. The influence of sodium dodecyl sulfate and methanol concentration on retention factor was established for both drugs using an interpretative approach assisted by chemometrics. The procedure was successfully validated following the guidelines of 2018 Bioanalytical Method Validation Guidance for Industry in terms of: linearity (determination coefficients over 0.99990), calibration range (1 – 50 mg/L), instrumental and method sensitivity, trueness (bias of −10.8 to + 2.4%), precision (relative standard deviation of < 10.2%), dilution integrity, carry-over effect, robustness and stability. It should be emphasized that the method uses low volumes of toxic and volatile solvents and can be achieved in a short period. The procedure was found useful for routine analysis, as it was cost-affordable, more eco-friendly and safer than hydroorganic HPLC, easy-to-handle and highly sample-throughput. Finally, it was applied to incurred samples of patients taking this medication.

SDS-induced hexameric oligomerization of myotoxin-II from Bothrops asper assessed by sedimentation velocity and nuclear magnetic resonance.

We report the solution behavior, oligomerization state, and structural details of myotoxin-II purified from the venom of Bothrops asper in the presence and absence of sodium dodecyl sulfate (SDS) and multiple lipids, as examined by analytical ultracentrifugation and nuclear magnetic resonance. Molecular functional and structural details of the myotoxic mechanism of group II Lys-49 phospholipase A2 homologues have been only partially elucidated so far, and conflicting observations have been reported in the literature regarding the monomeric vs. oligomeric state of these toxins in solution. We observed the formation of a stable and discrete, hexameric form of myotoxin-II, but only in the presence of small amounts of SDS. In SDS-free medium, myotoxin-II was insensitive to mass action and remained monomeric at all concentrations examined (up to 3mg/ml, 218.2μM). At SDS concentrations above the critical micelle concentration, only dimers and trimers were observed, and at intermediate SDS concentrations, aggregates larger than hexamers were observed. We found that the amount of SDS required to form a stable hexamer varies with protein concentration, suggesting the need for a precise stoichiometry of free SDS molecules. The discovery of a stable hexameric species in the presence of a phospholipid mimetic suggests a possible physiological role for this oligomeric form, and may shed light on the poorly understood membrane-disrupting mechanism of this myotoxic protein class.

Acoustic power dependent detachment of PSL particles adhered to glass surfaces by dissolved gas and anionic surfactant in an ultrasonic field

While numerous cleaning techniques have been proposed for the semiconductor cleaning process, the ultrasonic cleaning method has become an increasingly adopted technique that removes contaminated particles from semiconductor devices. Till date, little attention has been given to understand the role of surfactant and dissolved gas on the dynamics of cavitation bubbles at different ultrasonic powers. In this study, we propose a mechanism for the influence of SDS (sodium dodecyl sulfate) and dissolved H2 gas in deionized water (DIW) on the removal of PSL particles at different ultrasonic powers by evaluating the particle removal efficiency (PRE) via high-speed videography. It was observed that at US (ultrasonic) powers of 12 and 16 W, the PRE reached a maximum value at a SDS surfactant concentration of 20 ppm and then drastically decreased with increasing surfactant concentration. However, H2 gas dissolved DIW shows a high PRE compared to DIW at US powers of 4–16 W. Furthermore, the PRE reached a maximum value at 20 ppm SDS in a H2-DIW solution and then decreased with increasing surfactant concentration up to 100 ppm. However, the PRE decreased slightly with increasing SDS surfactant concentration when dissolved in H2-DIW. It was revealed that the US power and concentration of SDS significantly influence the removal of PSL particles. Furthermore, the size, cluster, population, and dynamic characteristics of bubbles affected the PRE differently in the presence of SDS and H2 gas. Our present research demonstrates a different approach towards the development of a more feasible ultrasonic cleaning process.

Assessment of the DCMD performances of poly(vinylidene difluoride) vapor-induced phase separation membranes with adjusted wettability via formation process parameter manipulation

Poly(vinylidene difluoride) (PVDF) membranes for direct contact membrane distillation (DCMD) are commonly modified to decrease their wettability by water. Yet, the vapor-induced phase separation (VIPS) process may be a suitable alternative to avoid complex and expensive modifications. Superhydrophobic membranes with a water contact angle >152° were prepared in one single step by adjusting the polymer concentration, dissolution temperature, relative humidity, and exposure time to vapors to 10 wt%, 40 °C, 80 % and 10 min, respectively with N-Methyl-2-pyrrolidone (NMP) as the solvent. Compared to commercial polytetrafluorethylene (PTFE) membrane, the VIPS PVDF membrane showed higher water vapor flux (38 LMH vs 36 LMH), lower flux decline ratio (22 % vs 39 %) and superior salt rejection (99.99 % vs. 99.90 %) in a 3 h-DCMD process. In wetting tests, the VIPS membrane failed for a sodium dodecyl sulfate concentration of 0.2 mM while 0.1 mM was enough to trigger wetting of the commercial membrane. The energy barrier to heterogeneous crystallization was slightly larger for the VIPS membrane, and a higher rejection was measured during scaling tests (99.8 % vs. 94.2 % for PTFE membrane). Finally, the VIPS membrane outperformed the commercial membrane in a long-term test (100 h). These results evidence the suitability of VIPS PVDF membranes for DCMD.

Enhanced adsorption of chlorogenic acid polyphenol by layered double hydroxide modified with sodium dodecyl sulfate

Polyphenols are a class of organic contaminants highly present in wastewater from industrial and agro-industrial processes. Adsorptive processes are employed to remove contaminants from effluents without the generation of by-products. Among the challenges in removal is the search for adsorbents that have affinity and favor the interaction with the contaminant. In this sense, this paper aimed to evaluate a layered double hydroxide modified with sodium dodecyl sulfate as an adsorbent material of the chlorogenic acid polyphenol. Carbonated magnesium-aluminum hydrotalcite was the layered double hydroxide employed for modification at different sodium dodecyl sulfate contents. The results showed that the modification with 50% w w-1 sodium dodecyl sulfate increased the adsorptive capacity of the modified layered double hydroxide from 0.030 mg g-1 to 2.3 mg g-1 after 24 hours of contact with the polyphenol. Thus, the use of sodium dodecyl sulfate for surface modification of layered double hydroxide indicated positive results that favor the application of the modified material in the removal of polyphenols.

Influence of sodium dodecyl sulphate on the surface and rheological behaviour of functionalised silica/polyacrylamide for drilling

AbstractThe stability of polymer composite can be enhanced by altering the structure of the functionalised material with surface modifiers, such as silane coupling agents, organic modifiers, surfactants and others. Surfactant has emerged as a potential modifier since it is eco‐friendly and simple. In this study, the surface of functionalised silica (SiO2) was modified using sodium dodecyl sulphate (SDS) in a polyacrylamide (PAM) composite. Characterisation of the drilling fluid was examined through Fourier‐transform infrared spectroscopy, surface tension, contact angle and rheological tests. According to the results, FTIR proved that the modification of PAM was successful. However, all modified PAM showed more hydrophilic properties with low surface tension than bare PAM. The rheological properties of all the modified PAM were varied over all the concentrations of SDS. Meanwhile, the rheological properties of the modified PAM were better than that of bare PAM. Due to the synergistic effect between the surfactant and functionalised material involved, the drilling fluid achieved low plastic viscosity in modified PAM. With a flat gel strength and better rheological properties, 0.2 wt% SDS in modified PAM is a great and promising formula in this study. In the future, further investigation can be conducted on bored pile drilling using this formulation.

Formation and Phase Transformation of MgCO3·3H2O Whiskers in the Presence of Sodium Dodecyl Sulfate.

Huge amounts of MgCl2·6H2O are produced annually as a byproduct or waste from KCl production in the Qinghai province of China. An ecological and economic way to solve this problem is transforming the abandoned MgCl2·6H2O to valuable MgCO3·3H2O whiskers. The formation and phase transformation of MgCO3·3H2O whiskers were studied in the crystallization process, in which MgCl2 and NH4HCO3 were precipitated in the presence of sodium dodecyl sulfate (SDS) at 50 °C. Results showed that porous spherical MgCO3·3H2O, MgCO3·3H2O whiskers, and flocculent rod-like 4MgCO3·Mg(OH)2·4H2O were formed with decreasing concentration of SDS as the crystallization proceeded. When the concentration of SDS was lower than the critical micellar concentration (6.5 mmol·L-1) at 60 min, SDS was beneficial for the growth in the [010] direction to form one-dimensional MgCO3·3H2O whiskers with a high aspect ratio, good uniformity, and a smooth surface (length, 60-70 μm; aspect ratio, 110-140).

Experimental study on the lateral migration of a bubble contaminated by surfactant in a linear shear flow

Adding a small amount of surfactant to a gas–liquid two-phase flow can markedly change the dynamic behavior of its bubbles. In this study, the lateral motion of a single bubble (deq = 1.99–3.33 mm, Reb = 200–420) contaminated by surfactant and rising in a linear shear flow is experimentally studied. Sodium dodecyl sulfate (SDS) is chosen as the surfactant with concentrations ranging from 10 to 50 ppm. A curved screen is used to generate a stable linear shear flow, and particle image velocimetry is used to measure the quality of the flow field. Bubble motion parameters, including trajectory, aspect ratio, instantaneous velocity, and terminal velocity, are captured using the shadow method with charge-coupled device cameras. The lift coefficient C L is obtained by a quasi-steady-state analysis. The results show that the presence of surfactant inhibits the lateral migration of bubbles rising in a shear flow and that increasing the SDS concentration and bubble equivalent diameter strengthens this inhibition effect. That is, the C L and the net lateral migration distance decreased with SDS concentration and bubble equivalent diameter. In addition, the variation trends of the quasi-steady drag coefficient, bubble terminal velocity, and bubble oscillation frequency with bubble equivalent diameter and SDS concentration also were analyzed.

Effect of polymer/surfactant complexation on diffusiophoresis of colloids in surfactant concentration gradients

HypothesisA concentration gradient of surfactants in the presence of polymers that non-covalently associate with surfactants will exhibit a continually varying distribution of complexes with different composition, charge, and size. Since diffusiophoresis of colloids suspended in a solute concentration gradient depends on the relaxation of the gradient and on the interactions between solutes and particles, polymer/surfactant complexation will alter the rate of diffusiophoresis driven by surfactant gradients relative to that observed in the same concentration gradient in the absence of polymers. ExperimentsA microfluidic device was used to measure diffusiophoresis of colloids suspended in solutions containing a gradient of sodium dodecylsulfate (SDS) in the presence or absence of a uniform concentration of Pluronic P123 poly(ethylene oxide-b-propylene oxide-b-ethylene oxide) nonionic triblock copolymers. To interpret the effect of P123 on the rate of colloid diffusiophoresis, electrophoretic mobility and dynamic light scattering measurements of the colloid/solute systems were performed, and a numerical model was constructed to account for the effects of complexation on diffusiophoresis. FindingsPolymer/surfactant complexation in solute gradients significantly enhanced diffusiophoretic transport of colloids. Large P123/SDS complexes formed at low SDS concentrations yielded low collective solute diffusion coefficients that prolonged the existence of strong concentration gradients relative to those without P123 to drive diffusiophoresis.

Synergy in the Microbial Cyclic Lipopeptide/Petroleum-Derived Surfactant Mixture Can Reduce the Total Surfactant Consumption

We report the synergistic effect of the addition of a microbial cyclic lipopeptide, surfactin (SF), to the most common petroleum-derived surfactant, sodium dodecyl sulfate (SDS). The addition of a small amount of SF (0.1 mol %) to an aqueous solution of SDS reduces the critical micelle concentration (CMC) of SDS from 10–3 to 10–6 M order. The addition of SF to SDS at various ratios lowered the surface tension at the CMC of SDS, indicating CMC reduction and, thus, the minimization of total SDS consumption without loss of surface activity. Surface tension measurement and nuclear magnetic resonance spectroscopy were conducted to analyze the synergy between SDS and SF in aqueous solutions as a function of composition. The interaction parameters of the mixed monolayer and mixed micelles were negative, indicating the occurrence of attractive interactions between SDS and SF, which were stronger than those among the individual surfactants. Moreover, the surface tension at the CMC, area occupied per surfactant molecule, difference in the interaction parameter, and 1H NMR chemical shift values of the SDS/SF mixtures as a function of their composition exhibited an extremum at a mole fraction of 0.7. These results suggest that SF has the peculiarities of encapsulation of the anionic surfactant of SDS within the inner cavity and can screen the electrostatic repulsion of SDS via the formation of their inclusion complex at SDS:SF = 2:1, which facilitates the formation of mixed monolayers and micelles in a more stable state.

Remediation of contaminated sand by Cd ions with variation operation: Batch and flushing column with foam and without foam of SDS surfactant

An anionic surfactant, Sodium dodecyl sulfate (SDS), was applied to remove Cd ions as contaminants on the sand surface. The remediation operation approach was used, such as batch, flushing column without foam, and with foam of SDS solution. Increasing the SDS concentration is possible to improve the removal ability of Cd ions from the sand surface. For batch, the operation performs the higher removal ability by increasing the shaking rotation per minute (rpm). Fluctuation of the percentage removal efficiency (% RE) was shown by using a flushing column without foam at each flow rate variation. The channeling effect during flushing in the column was proved to be the cause of fluctuation in the removal efficiency. Flushing with foam is possible to increase the removal efficiency from 10% by batch and flushing without foam to about 70% with foam. The increasing flow rate of surfactant SDS solution is possible to increase the removal efficiency and flow to the intra-particle area of sand and then decrease the channeling effect. Flushing in column approach with foam by anionic surfactant SDS shows the higher ability and more efficiency in the removal of Cd ions on the sand surface.

A novel UiO-66-NH2/graphene oxide composite thin membrane for retarding membrane wetting in membrane distillation

Membrane distillation (MD) is considered an emerging desalination technology. However, the presence of surfactants allows liquid to penetrate the membrane, resulting in membrane wetting, which hinders the commercialization of MD. In this study, we use very few modified materials to prepare novel Janus thin membranes that immobilize modified materials (graphene oxide (GO) and UiO-66-NH2) on polytetrafluoroethylene (PTFE) hydrophobic base membranes via crosslinkers. The composite thin membrane properties with eight different ratios and contents of GO and UiO-66-NH2 were fabricated and tested by a feed solution of sodium chloride containing a high concentration of sodium dodecyl sulfate. An optimal ratio of Janus membrane with high flux without affecting the effluent water quality was obtained. The Janus membrane exhibited excellent anti-wetting properties compared to the original PTFE membrane. A desalination rate of up to 99.9% was still available even under 48 h of long-term operating conditions by maintaining a flux of approximately 21.2 L/(m2·h). The anti-wetting mechanism of this membrane was further confirmed by the modified XDLVO model. It suggested that the novel Janus membrane could be a highly promising substitute to the MD process for the resource-based treatment of surfactant-containing wastewater, which played an important role in promoting its application.

Study on the bactericidal activity of dodecyl dipropylene triamine and anionic mixed surfactant systems

In this study, we anticipated that cocamidopropyl betaine (CAPB) and isomeric alcohol ethoxylates (TO) could protect the antibacterial properties of dodecyl dipropylene triamine (BDA) under the influence of anionic surfactants. Different concentrations of anionic surfactants such as sodium lauryl polyoxyethylene ether sulfate (AES) and sodium dodecyl sulfate (SDS) were added to a mixture of the cationic surfactants BDA and benzalkonium chloride (BZK) with two protective agents: a branched nonionic surfactant TO and a zwitterionic surfactant CAPB. Opticaldensity (OD) and Cell Counting Kit-8 (CCK-8) methods were used to evaluate the antibacterial activity of these systems against sulfate-reducing bacteria (SRB) such as Escherichia coli, Staphylococcus aureus, and Desulfovibrio sp. The protective mechanisms of the different protective agents were studied by measuring their respective viscosities. The protective agents (TO and CAPB) had a negative effect on the biocidal performance of the BZK (C12-C14) but had an excellent protective effect in the presence of anionic surfactants. In the BDA systems (AES and SDS concentrations of 100 mM), the BDA-CAPB-AES, BDA-CAPB-SDS, BDA-TO-AES, and BDA-TO-SDS systemseliminated almost all E.coli and S.aureus bacteria within 2 min of exposure, among which the BDA-CAPB-AES and BDA-TO-AES systems showed the strongest bactericidal activity against sulfate reducingbacteria (SRB). Therefore, these multicomponent surfactant antibacterial systems can potentially be used to replace traditional cationic surfactant systems in the chemical industry, thereby reducing the microbial corrosion caused by SRB.

Can sodium 1-alkylsulfonates participate in the sodium dodecyl sulfate micelle formation?

The aggregation behavior of sodium dodecyl sulfate (SDS) was studied in an aqueous solution in the presence of increasing concentrations of selected sodium 1-alkylsulfonates, namely sodium 1-octanesulfonate, sodium 1-decanesulfonate, and sodium 1-dodecanesufonate. The critical micelle concentration (CMC) of SDS was determined by conductivity and fluorescence intensity measurements. The steady-state fluorescence quenching experiments with pyrene as a fluorescent probe were performed to obtain micellar aggregation numbers (Nagg) of the surfactant. The thermodynamic parameters of micellization (ΔGmic0 for all studied systems; ΔHmic0 and ΔSmic0 for sodium 1-dodecanesufonate) have been determined and compared. The influence of alkyl chain length and concentration of the selected sodium 1-alkylsulfonates on the values of CMC, Nagg, ΔGmic0, ΔHmic0, and ΔSmic0 of SDS has been discussed. As it was found, all selected for the experiments electrolytes decrease significantly the CMC of the surfactant, while an opposite effect is observed for Nagg values. The obtained experimental results have been supported by theoretical calculations. Interestingly, it has been proven that solely the molecules of sodium 1-dodecanesufonate (of the same carbon chain length) may act as the SDS mimetics – they are not recognized by SDS as the ones with a different structure and consequently are allowed to participate in the formation of the surfactant’s micelles.

Preparation of extracellular matrix of fish swim bladders by decellularization with supercritical carbon dioxide

Fish swim bladders used to be considered as byproducts or waste in fishery; however, they are potential materials for biological medicine with abundant collagen. In this work, an efficient noncytotoxic decellularization process using sodium dodecyl sulfate (SDS) ternary system assisted with supercritical carbon dioxide (scCO2) as the green extraction fluid and ethanol (ET) as the cosolvent has been developed to harvest acellular fish swim bladders (AFSBs). The experimental results show that the tissue treated by SDS assisted with scCO2 and ethanol at 37 °C and 25 MPa can be decellularized thoroughly and maintains intact fibers and uniform pore distribution, which resulting in a tensile strength of 5.61 MPa and satisfactory biocompatibility. Meanwhile, the residual SDS content in scCO2/SDS/ET ternary system is 0.0122% which is significantly lower than it in scCO2/SDS system due to the enhanced mass transfer rate of SDS in tissues by scCO2 with ethanol. The synergy between SDS and ethanol can enhance the diffusion coefficient and the solubility of SDS in scCO2, which reduced the contact time between SDS and tissues. Meaningfully, the results obtained in this work can not only provide a novel strategy to produce acellular matrix with superior properties, but also offer a further understanding of the decellularization through scCO2 extraction processing with the synergy of suitable detergent/cosolvent.Graphical

Experimental study on subcooled pool boiling heat transfer of sodium dodecyl sulfate surfactant solution

The pool boiling heat transfer coefficient (HTC) and critical heat flux (CHF) of sodium dodecyl sulfate (SDS) surfactant solution under different concentrations and subcooling conditions were experimentally studied. The concentration of SDS was in the range of 0 to 3000 ppm, and the subcooling degree was in the range of 2 to 10 °C. The heat transfer coefficient under different subcooling conditions was theoretically analyzed, and the real-time fluctuation of the wall temperature is discussed in detail. It is found that the subcooling has little effect on the natural convection of pool boiling but significantly impacts the nucleate boiling and that the phenomenon of temperature overshoot (TOS) is stronger in the SDS solution than that in de-ionized water. Furthermore, the origin and development process of TOS were deeply analyzed by showing the development process diagram. Meanwhile, the CHF phenomena were visualized and traced experimentally. The influence of different subcooling degrees and SDS concentrations on the CHF was deeply explored, and the development process diagram of the vapor film under CHF conditions was plotted. The results provide detailed theoretical support for the HTC and CHF of SDS solution under subcooling conditions.

Effects of Sodium Dodecyl Sulfate on the Enzyme Catalysis and Conformation of a Recombinant γ-Glutamyltranspeptidase from Bacillus licheniformis.

The study of interactions between proteins and surfactants is of relevance in a diverse range of applications including food, enzymatic detergent formulation, and drug delivery. In spite of sodium dodecyl sulfate(SDS)-induced unfolding has been studied in detail at the protein level, deciphering the conformation-activity relationship of a recombinant γ-glutamyltranspeptidase (BlrGGT) from Bacillus licheniformis remains important to understand how the transpeptidase activity is related to its conformation. In this study, we examined the enzyme catalysis and conformational transition of BlrGGT in the presence of SDS. Enzymatic assays showed that the transpeptidase activity of BlrGGT was greatly affected by SDS in a concentration-dependent manner with approximately 90% inactivation at 6mM. Native polyacrylamide gel electrophoresis of SDS-treated samples clearly revealed that the heterodimeric enzyme was apparently dissociated into two different subunits at concentrations above 2mM. The study of enzyme kinetics showed that SDS can act as a mixed-type inhibitor to reduce the catalytic efficiency of BlrGGT. Moreover, the t1/2 value of the enzyme at 55°C was greatly reduced from 495.1min to 7.4min in the presence of 1mM SDS. The I3/I1 ratio ofpyreneexcimerfluorescence emission changed around 3.7mMSDSin the absence ofBlrGGT and the inflection point of enzyme samples was reduced to less than 2.7mM. The Far-UV CD spectrum of the native enzyme had two negative peaks at 208 and 222nm, respectively; however, both negative peaks increased in magnitude with increasing SDS concentration and reached maximal values at above 4.0mM. Theintrinsic fluorescence spectraof tryptophan further demonstrated that the SDS-induced enzyme conformational transition occurred at approximately 5.1mM. Tween 20 significantly suppressed the interaction of BlrGGT with SDS by forming mixed micelles at a molar ratio of 1.0. Taken together, this study definitely promotes our better understanding of the relationship between the conformation and catalysis of BlrGGT.