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Fulltext Whole And Parotid Saliva - Protein Profiles As Separated On 5-20% SDS-Polyacrylamide Gradient gel Electrophoresis And Using Maldi-tof Mass Spectrometry

Huq, N.L., DeAngelis, A., Rahim, Z.H.A., Ung, M., Lucas, J., Cross, K.J., et al.

Ann Dent, 2004;11(1):-.
MyJurnal

The aim was to examine the protein profiles of whole and parotid saliva using Sodium Dodecyl Sulphate Polyacrylamide Gel Electrophoresis (SDS-PAGE) and MALDI-TOF mass spectrometry. The banding patterns of proteins exhibited by the unstimulated whole saliva samples on the gel remained quite constant but the intensity of the protein bands were slightly different from one sample to another. Comparison of the protein profiles of unstimulated whole saliva and stimulated parotid saliva showed almost similar banding pattern. The exception is the presence of a pink protein band in the 65-67 kD region in the stimulated parotid saliva samples which was also observed in the unstimulated whole saliva sample contributed by a cerebral palsy patient. Analysis of the saliva samples using MALDI-TOF mass spectrometry also revealed that the stimulated parotid saliva samples exhibited some peaks that were in the same region as those for the unstimulated whole saliva sample of the cerebral palsy subject. This may imply that there is ineffective control of the parotid secretion in cerebral palsy subject under unstimulated condition. The SDS-PAGE and MALDI-TOF analyses may provide more information on the profiles of the salivary proteins which could be beneficial in the diagnosis of salivary gland dysfunction.

Matched MeSH terms: Sodium Dodecyl Sulfate
Fulltext Unique Halloysite Nanotubes⁻Polyvinyl Alcohol⁻Polyvinylpyrrolidone Composite Complemented with Physico⁻Chemical Characterization

Gaaz TS, Kadhum AAH, Michael PKA, Al-Amiery AA, Sulong AB, Nassir MH, et al.

Polymers (Basel), 2017 Jun 06;9(6).
PMID: 30970887 DOI: 10.3390/polym9060207

A halloysite nanotubes⁻polyvinyl alcohol⁻polyvinylpyrrolidone (HNTs⁻PVA⁻PVP) composite has been investigated for a quite long time aiming at improving the physico⁻chemical characterization of HNTs. In this work, HNTs⁻PVA⁻PVP composite were prepared based on a unique procedure characterized by crosslinking two polymers with HNTs. The composite of two polymers were modified by treating HNTs with phosphoric acid (H₃PO₄) and by using malonic acid (MA) as a crosslinker. The composite was also treated by adding the dispersion agent sodium dodecyl sulfate (SDS). The HNTs⁻PVA⁻PVP composite shows better characteristics regarding agglomeration when HNTs is treated in advance by H₃PO₄. Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), transmission electron microscopy (TEM), field emission scanning electron microscopy (FESEM), brunauer⁻emmett⁻teller (BET), size distribution, and atomic force microscopy (AFM) are used to characterize the physio-chemical properties of the composite. FTIR shows additional peaks at 2924.29, 1455.7, and 682.4 cm-1 compared to the neat HNTs due to adding MA. Despite that, the XRD spectra do not show a significant difference, the decrease in peak intensity could be attributed to the addition of semi-crystalline PVA and the amorphous PVP. The images taken by TEM and FESEM show the possible effects of MA on the morphology and internal feature of HNTs⁻PVA⁻PVP composite treated by MA by showing the deformation of the matrix. The BET surface area increased to 121.1 m²/g compared to the neat HNTs at 59.1 m²/g. This result, the second highest recorded result, is considered a breakthrough in enhancing the properties of HNTs⁻PVA⁻PVP composite, and treatment by MA crosslinking may attribute to the size and the number of the pores. The results from these techniques clearly showed that a significant change has occurred for treated HNTs⁻PVA⁻PVP composite where MA was added. The characterization of HNTs⁻PVA⁻PVP composite with and without treating HNTs and using crosslinker may lead to a better understanding of this new composites as a precursor to possible applications in the dentistry field.

Matched MeSH terms: Sodium Dodecyl Sulfate
The use of sonication treatment to decellularize aortic tissues for preparation of bioscaffolds

Azhim A, Syazwani N, Morimoto Y, Furukawa KS, Ushida T

J Biomater Appl, 2014 Jul;29(1):130-41.
PMID: 24384523 DOI: 10.1177/0885328213517579

A novel decellularization method using sonication treatment is described. Sonication treatment is the combination of physical and chemical agents. These methods will disrupt cell membrane and release cell contents to external environments. The cell removal was facilitated by subsequent rinsing of sodium dodecyl sulfate detergents. Sonication treatment is used in the preparation of complete decellularized bioscaffolds. The aim of this study is to confirm the usefulness of sonication treatment for preparation of biological scaffolds. In this study, samples of aortic tissues are decellularized by sonication treatment at frequency of 170 kHz in 0.1% and 2% sodium dodecyl sulfate detergents for 10-h treatment time. The relation between decellularization and sonication parameters such as dissolved oxygen concentration, conductivity, and pH is investigated. Histological analysis and biomechanical testing is performed to evaluate cell removal efficiency as well as changes in biomechanical properties. Minimal inflammation response elicit by bioscaffolds is confirmed by xenogeneic implantation and immunohistochemistry. Sonication treatment is able to produce complete decellularized tissue suggesting that these treatments could be applied widely as one of the decellularization method.

Matched MeSH terms: Sodium Dodecyl Sulfate
The rubber elongation factor of rubber trees (Hevea brasiliensis) is the major allergen in latex

Czuppon AB, Chen Z, Rennert S, Engelke T, Meyer HE, Heber M, et al.

J Allergy Clin Immunol, 1993 Nov;92(5):690-7.
PMID: 8227860

BACKGROUND: Allergy to latex-containing articles is becoming more and more important because it can result in unexpected life-threatening anaphylactic reactions in sensitized individuals.
METHODS: A protein of 58 kd with an isoelectric point of 8.45 was purified from raw latex and from latex gloves and identified as the major allergen, completely blocking specific IgE antibodies in the serum of latex-sensitized subjects. The allergen is a noncovalent homotetramer molecule, in which the 14.6 kd monomer was identified, by amino acid composition and sequence homologies of tryptic peptides, to be the rubber elongation factor found in natural latex of the Malaysian rubber tree.
RESULTS: Competitive immunoinhibition tests showed that the starch powder covering the finished gloves is the airborne carrier of the allergen, resulting in bronchial asthma on inhalation. The purified allergen can induce allergic reactions in the nanogram range.
CONCLUSION: The identification of the allergen (Hev b I) may help to eliminate it during the production of latex-based articles in the future.

Matched MeSH terms: Sodium Dodecyl Sulfate
Fulltext The effect of sodium dodecyl sulfate (SDS) and cetyltrimethylammonium bromide (CTAB) on the Properties of ZnO synthesized by hydrothermal method

Ramimoghadam D, Hussein MZ, Taufiq-Yap YH

Int J Mol Sci, 2012;13(10):13275-93.
PMID: 23202952 DOI: 10.3390/ijms131013275

ZnO nanostructures were synthesized by hydrothermal method using different molar ratios of cetyltrimethylammonium bromide (CTAB) and Sodium dodecyl sulfate (SDS) as structure directing agents. The effect of surfactants on the morphology of the ZnO crystals was investigated by field emission scanning electron microscopy (FESEM) and transmission electron microscopy (TEM) techniques. The results indicate that the mixture of cationic-anionic surfactants can significantly modify the shape and size of ZnO particles. Various structures such as flakes, sheets, rods, spheres, flowers and triangular-like particles sized from micro to nano were obtained. In order to examine the possible changes in other properties of ZnO, characterizations like powder X-ray diffraction (PXRD), thermogravimetric and differential thermogravimetric analysis (TGA-DTG), FTIR, surface area and porosity and UV-visible spectroscopy analysis were also studied and discussed.

Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry*
Fulltext Synergetic Effect of Surfactant Concentration, Salinity, and Pressure on Adsorbed Methane in Shale at Low Pressure: An Experimental and Modeling Study

Abdulelah H, Negash BM, Yekeen N, Al-Hajri S, Padmanabhan E, Al-Yaseri A

ACS Omega, 2020 Aug 18;5(32):20107-20121.
PMID: 32832765 DOI: 10.1021/acsomega.0c01738

The influence of an anionic surfactant, a cationic surfactant, and salinity on adsorbed methane (CH4) in shale was assessed and modeled in a series of systematically designed experiments. Two cases were investigated. In case 1, the crushed Marcellus shale samples were allowed to react with anionic sodium dodecyl sulfate (SDS) and brine. In case 2, another set of crushed Marcellus shale samples were treated with cetyltrimethylammonium bromide (CTAB) and brine. The surfactant concentration and salinity of brine were varied following the Box-Behnken experimental design. CH4 adsorption was then assessed volumetrically in the treated shale at varying pressures (1-50 bar) and a constant temperature of 30 °C using a pressure equilibrium cell. Mathematical analysis of the experimental data yielded two separate models, which expressed the amount of adsorbed CH4 as a function of SDS/CTAB concentration, salinity, and pressure. In case 1, the highest amount of adsorbed CH4 was about 1 mmol/g. Such an amount was achieved at 50 bar, provided that the SDS concentration is kept close to its critical micelle concentration (CMC), which is 0.2 wt %, and salinity is in the range of 0.1-20 ppt. However, in case 2, the maximum amount of adsorbed CH4 was just 0.3 mmol/g. This value was obtained at 50 bar and high salinity (∼75 ppt) when the CTAB concentration was above the CMC (>0.029 wt %). The findings provide researchers with insights that can help in optimizing the ratio of salinity and surfactant concentration used in shale gas fracturing fluid.

Matched MeSH terms: Sodium Dodecyl Sulfate
Surfactants with aromatic headgroups for optimizing properties of graphene/natural rubber latex composites (NRL): Surfactants with aromatic amine polar heads

Ardyani T, Mohamed A, Bakar SA, Sagisaka M, Umetsu Y, Mamat MH, et al.

J Colloid Interface Sci, 2019 Jun 01;545:184-194.
PMID: 30878784 DOI: 10.1016/j.jcis.2019.03.012

HYPOTHESIS: The compatibility of surfactants and graphene surfaces can be improved by increasing the number of aromatic groups in the surfactants. Including aniline in the structure may improve the compatibility between surfactant and graphene further still. Surfactants can be modified by incorporating aromatic groups in the hydrophobic chains or hydrophilic headgroups. Therefore, it is of interest to investigate the effects of employing anilinium based surfactants to disperse graphene nanoplatelets (GNPs) in natural rubber latex (NRL) for the fabrication of electrically conductive nanocomposites.
EXPERIMENTS: New graphene-philic surfactants carrying aromatic moieties in the hydrophilic headgroups and hydrophobic tails were synthesized by swapping the traditional sodium counterion with anilinium. 1H NMR spectroscopy was used to characterize the surfactants. These custom-made surfactants were used to assist the dispersion of GNPs in natural rubber latex matrices for the preparation of conductive nanocomposites. The properties of nanocomposites with the new anilinium surfactants were compared with commercial sodium surfactant sodium dodecylsulfate (SDS), sodium dodecylbenzenesulfonate (SDBS), and the previously synthesized aromatic tri-chain sodium surfactant TC3Ph3 (sodium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate). Structural properties of the nanocomposites were studied using Raman spectroscopy, field emission scanning electron microscopy (FESEM), and high-resolution transmission electron microscopy (HRTEM). Electrical conductivity measurements and Zeta potential measurements were used to assess the relationships between total number of aromatic groups in the surfactant molecular structure and nanocomposite properties. The self-assembly structure of surfactants in aqueous systems and GNP dispersions was assessed using small-angle neutron scattering (SANS).
FINDINGS: Among these different surfactants, the anilinium version of TC3Ph3 namely TC3Ph3-AN (anilinium 1,5-dioxo-1,5-bis(3-phenylpropoxy)-3-((3phenylpropoxy)carbonyl) pentane-2-sulfonate) was shown to be highly efficient for dispersing GNPs in the NRL matrices, increasing electrical conductivity eleven orders of magnitude higher than the neat rubber latex. Comparisons between the sodium and anilinium surfactants show significant differences in the final properties of the nanocomposites. In general, the strategy of increasing the number of surfactant-borne aromatic groups by incorporating anilinium ions in surfactant headgroups appears to be effective.

Matched MeSH terms: Sodium Dodecyl Sulfate
Surface active complexes formed between keratin polypeptides and ionic surfactants

Pan F, Lu Z, Tucker I, Hosking S, Petkov J, Lu JR

J Colloid Interface Sci, 2016 Dec 15;484:125-134.
PMID: 27599381 DOI: 10.1016/j.jcis.2016.08.082

Keratins are a group of important proteins in skin and hair and as biomaterials they can provide desirable properties such as strength, biocompatibility, and moisture regaining and retaining. The aim of this work is to develop water-soluble keratin polypeptides from sheep wool and then explore how their surface adsorption behaves with and without surfactants. Successful preparation of keratin samples was demonstrated by identification of the key components from gel electrophoresis and the reproducible production of gram scale samples with and without SDS (sodium dodecylsulphate) during wool fibre dissolution. SDS micelles could reduce the formation of disulphide bonds between keratins during extraction, reducing inter-molecular crosslinking and improving keratin polypeptide solubility. However, Zeta potential measurements of the two polypeptide batches demonstrated almost identical pH dependent surface charge distributions with isoelectric points around pH 3.5, showing complete removal of SDS during purification by dialysis. In spite of different solubility from the two batches of keratin samples prepared, very similar adsorption and aggregation behavior was revealed from surface tension measurements and dynamic light scattering. Mixing of keratin polypeptides with SDS and C12TAB (dodecyltrimethylammonium bromide) led to the formation of keratin-surfactant complexes that were substantially more effective at reducing surface tension than the polypeptides alone, showing great promise in the delivery of keratin polypeptides via the surface active complexes. Neutron reflection measurements revealed the coexistence of surfactant and keratin polypeptides at the interface, thus providing the structural support to the observed surface tension changes associated with the formation of the surface active complexes.

Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry*
Fulltext Supramolecular Electrochemical Sensor for Dopamine Detection Based on Self-Assembled Mixed Surfactants on Gold Nanoparticles Deposited Graphene Oxide

Uppachai P, Srijaranai S, Poosittisak S, Md Isa I, Mukdasai S

Molecules, 2020 May 29;25(11).
PMID: 32485804 DOI: 10.3390/molecules25112528

A new supramolecular electrochemical sensor for highly sensitive detection of dopamine (DA) was fabricated based on supramolecular assemblies of mixed two surfactants, tetra-butylammonium bromide (TBABr) and sodium dodecyl sulphate (SDS), on the electrodeposition of gold nanoparticles on graphene oxide modified on glassy carbon electrode (AuNPs/GO/GCE). Self-assembled mixed surfactants (TBABr/SDS) were added into the solution to increase the sensitivity for the detection of DA. All electrodes were characterized by scanning electron microscopy (SEM), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). The supramolecular electrochemical sensor (TBABr/SDS⋅⋅⋅AuNPs/GO/GCE) showed excellent electrocatalytic activity toward the oxidation of DA. Under the optimum conditions, the concentration of DA was obtained in the range from 0.02 µM to 1.00 µM, with a detection limit of 0.01 µM (3s/b). The results displayed that TBABr/SDS⋅⋅⋅AuNPs/GO/GCE exhibited excellent performance, good sensitivity, and reproducibility. In addition, the proposed supramolecular electrochemical sensor was successfully applied to determine DA in human serum samples with satisfactory recoveries (97.26% to 104.21%).

Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry
Fulltext Statistical investigation of extraction parameters of keratin from chicken feather using Design-Expert

Kamarudin NB, Sharma S, Gupta A, Kee CG, Chik SMSBT, Gupta R

3 Biotech, 2017 Jun;7(2):127.
PMID: 28573397 DOI: 10.1007/s13205-017-0767-9

Uncontrolled disposal of feathers from the poultry industry and slaughterhouses is environmentally undesirable. The feathers are composed of approximately 90% of keratin which is an important ingredient of cosmetics, shampoos and hair treatment creams. This study aimed to determine the optimum conditions for the extraction of keratin from chicken feathers. The extraction of keratin using various reducing agents was studied using statistical experimental design. In the extraction process, pH, temperature, ratio of reducing agents, mass of chicken feathers and incubation time were analyzed. The keratin in the total extracted protein was purified by size exclusion chromatography, sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) and further characterized using amino acids profile analysis. The surface morphology and chemical composition were studied by scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) analysis. Sodium sulfide (Na2S) yielded 84.5% of keratin as compared to sodium hydroxide (43.8), urea mixture (50.6), mixture of sodium dodecyl sulfate (SDS) and sodium bisulfite (18.3) and a mixture of Na2S and sodium hydroxide (41.5%) under optimized conditions. The optimum yield of keratin was achieved at 80.9 °C in 9.5 h with 0.05 M sodium sulfide using response surface methodology (RSM). Among the five parameters screened, pH was found not to be significant because the p value was greater than 0.05.

Matched MeSH terms: Sodium Dodecyl Sulfate
Sodium dodecyl sulphate as a rapid clearing agent for studying the hard parts of monogeneans and nematodes

Wong WL, Tan WB, Lim LH

J Helminthol, 2006 Mar;80(1):87-90.
PMID: 16469180

Hard structures of helminths have often been used for taxonomic identification but are usually not clearly defined when treated with conventional methods such as ammonium picrate-glycerin for monogeneans and glycerin for nematodes. The present study reports a rapid and simple technique to better resolve the hard parts of selected monogeneans and nematodes using 5-10% alkaline sodium dodecyl sulphate (SDS). In comparison with established methods, SDS-treated worms become more transparent. In monogeneans treated with SDS, clear details of the hooks, hook filaments, anchors, bars and the sclerotized copulatory organs could be observed. In SDS-treated nematodes, spicules and ornamentations of the buccal capsules could be clearly seen.

Matched MeSH terms: Sodium Dodecyl Sulfate*
Sodium dodecyl sulfate-coated-cationized agroforestry residue as adsorbent for benzene-adsorptive sequestration from aqueous solution

Kong H, Saman N, Tee PN, Cheu SC, Song ST, Johari K, et al.

Environ Sci Pollut Res Int, 2019 Apr;26(11):11140-11152.
PMID: 30796666 DOI: 10.1007/s11356-019-04248-5

The aim of this work is to convert agroforestry residue to a novel adsorbent (M-1CTA-SDS-BT) used for adsorptive benzene sequestration from aqueous solution. In this study, the anionic surfactant-coated-cationized banana trunk was synthesized and characterized for batch adsorption of benzene from aqueous solution. The surface morphology, surface chemistry, surface area, and pore properties of the synthesized adsorbents were examined. It was proven that surface cationization successfully increased the benzene adsorption capacity of sodium dodecyl sulfate-coated adsorbents. The Langmuir isotherm model satisfactorily described the equilibrium adsorption data. The maximum benzene adsorption capacity (qmax) of 468.19 μmol/g was attained. The kinetic data followed the pseudo-second-order kinetic model in which the rate-limiting step was proven to be the film diffusion. The batch-adsorbent regeneration results indicated that the M-1CTA-SDS-BT could withstand at least five adsorption/desorption cycles without drastic adsorption capacity reduction. The findings demonstrated the adsorptive potential of agroforestry-based adsorbent as a natural and cheap material for benzene removal from contaminated water.

Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry*
Fulltext Purification and kinetics of the PHB depolymerase of Microbacterium paraoxydans RZS6 isolated from a dumping yard

Sayyed RZ, Wani SJ, Alyousef AA, Alqasim A, Syed A, El-Enshasy HA

PLoS One, 2019;14(6):e0212324.
PMID: 31211775 DOI: 10.1371/journal.pone.0212324

Poly-β-hydroxybutyrate (PHB) depolymerase is known to decompose PHB, biodegradable polymers and therefore has great commercial significance in the bioplastic sector. However, reports on PHB depolymerases from isolates obtained from plastic-contaminated sites that reflect the potential of the source organism is scarce. In this study, we evaluated the production of extracellular PHB depolymerase from Microbacterium paraoxydans RZS6 isolated from the plastic-contaminated site in the municipal area of Shahada, Maharashtra, India, for the first time. The isolate was identified using 16S rRNA gene sequencing, gas chromatographic analysis of fatty acid methyl esters (GC-FAME), and BIOLOG method. Ithydrolyzed PHB on minimal salt medium (MSM) containing PHB as the only source of carbon. The isolate produced PHB depolymerase at 45°C during 48 h of incubation. The enzyme was purified most efficiently using octyl-sepharose CL-4B column, with the highest purification yield of 6.675 Umg-1mL-1. The activity of the enzyme was enhanced in the presence of Ca2+ and Mg2+ ions but inhibited by Fe2+ (1 mM) ions and mercaptoethanol (1000 rpm). the nzyme kinetic analysis revealed that the enzyme was a metalloenzyme; requiring Mg2+ ions, that showed optimum enzyme activity at 30°C (mesophilic) and under neutrophilic (pH 7) conditions. Scale-up from the shake-flask level to a laboratory-scale bioreactor further enhanced the enzyme yield by 0.809 UmL-1. The molecular weight of the enzyme (40 kDa), as estimated by sodium dodecyl sulfate-polyacrylamide gel electrophoresis, closely resembled the PHB depolymerase of Aureobacterium saperdae. Our findings highlighted the applicability of M. paraoxydans as a producer of extracellular PHB depolymerase having potential of degrading PHB under diverse conditions.

Matched MeSH terms: Sodium Dodecyl Sulfate
Proteomic analysis of stored core oil palm trunk (COPT) sap identifying proteins Related to stress, disease resistance and differential gene/protein expression

Marhaini Mostapha, Noorhasmiera Abu Jahar, Sarani Zakaria, Sharifah Nabihah Syed Jaafar, Kamalrul Azlan Azizan, Wan Mohd Aizat

Sains Malaysiana, 2018;47:1259-1268.

Oil palm is the major crop grown and cultivated in various Asian countries such as Malaysia, Indonesia and Thailand.
The core of oil palm trunk (COPT) consists of high sugar content, hence suitable for synthesis of fine chemicals and
biofuels. Increase of sugar content was reported previously during prolonged COPT storage. However, until now, there
has been no report on protein profiles during storage. Therefore, in this study, protein expression of the COPT during the
storage period of one to six weeks was investigated using sodium dodecyl sulphate polyacrylamide gel electrophoresis
(SDS-PAGE) coupled with optical density quantification and multivariate analyses for measuring differentially expressed
proteins. Accordingly, protein bands were subjected to tryptic digestion followed by tandem mass spectrometry (nanoLCMS/MS)
protein identification. The results from SDS-PAGE showed consistent protein bands appearing across the biological
replicates ranging from 10.455 to 202.92 kDa molecular weight (MW) regions. The findings from the principal component
analysis (PCA) plot illustrated the separation pattern of the proteins at weeks 4 and 5 of storage, which was influenced
mainly by the molecular weights of 14.283, 25.543, 29.757, 30.549, 31.511, 34.585 and 84.395 kDa, respectively. The
majority of these proteins are identified as those involved in stress- and defense-related, disease resistance, as well
as gene/protein expression processes. Indeed, these proteins were mostly upregulated during the later storage period
suggesting that long-term storage may influence the molecular regulation of COPT sap.

Matched MeSH terms: Sodium Dodecyl Sulfate
Protein purification for the Lowry assay: acid precipitation of proteins in the presence of sodium dodecyl sulfate and other biological detergents

Yeang HY, Yusof F, Abdullah L

Anal Biochem, 1998 Dec 15;265(2):381-4.
PMID: 9882418
Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry*
Fulltext Properties of proteolytic enzyme from ginger (Zingiber officinale Roscoe)

Nafi’, A., Foo, H.L., Jamilah, B., Ghazali. H.M.

International Food Research Journal, 2013;20(1):363-368.
MyJurnal

Proteases in ginger rhizome have the potentials in industrial applications. This study was conducted to extract and characterize the proteolytic enzyme from ginger (Zingiber officinale Roscoe). Ginger protease (GP) was extracted from ginger rhizome by homogenization with 100 mM potassium phosphate buffer pH 7.0 containing 10 mM cysteine and 5 mM EDTA which were found to be the most efficient extraction buffer and stabilizers. After centrifugation at 10,500 x g, protein in the crude extract was precipitated using 60% ammonium sulfate following which the precipitate was redissolved in 50 mM potassium phosphate buffer pH 7.0, dialyzed and then lyophilized. The extraction method yielded 0.94% (w/w of fresh weight) of GP with a specific activity of 27.6 ± 0.1 Unit/mg protein where 1 Unit is defined as the amount of protease causing an increase in absorbance by 1 unit per minute using azocasein as the substrate. Results show that the GP was completely inhibited by heavy metal cations i.e. Cu2+and Hg2+, and a thiol blocking agent or inhibitor, n-ethyl maleimide (NEM), indicating that GP is most probably a cysteine protease. The enzyme has an optimum temperature at 60⁰C and the optimum pH ranged between pH 6 to 8. Monovalent cations (K+ and Na+) have no significant effect on activity of GP, but divalent and trivalent cations showed moderate inhibitory effect. Detergents such as sodium dodecyl sulfate increased the activity of GP while Tween 80 and Tween 20 slightly reduced the activity.

Matched MeSH terms: Sodium Dodecyl Sulfate
Plasmid profiling and curing of Lactobacillus strains isolated from the gastrointestinal tract of chicken

Chin SC, Abdullah N, Siang TW, Wan HY

J Microbiol, 2005 Jun;43(3):251-6.
PMID: 15995642

In this study, we assessed the susceptibility of 12 Lactobacillus strains, all of which had been isolated from the gastrointestinal tracts of chicken, to three antibiotics (chloramphenicol, erythromycin and tetracycline) used commonly as selective markers in transformation studies of lactic acid bacteria. Among these strains, 17%, 58%, and 25% were found to exhibit a high degree of resistance to 200 microg/ml of tetracycline, erythromycin, and chloramphenicol, respectively. Seven of the 12 Lactobacillus strains exhibiting resistance to at least 50 microg/ml of chloramphenicol or erythromycin, and five strains exhibiting resistance to at least 50 microg/ml of tetracycline, were subsequently subjected to plasmid curing with chemical curing agents, such as novobiocin, acriflavin, SDS, and ethidium bromide. In no cases did the antibiotic resistance of these strains prove to be curable, with the exception of the erythromycin resistance exhibited by five Lactobacillus strains (L. acidophilus I16 and I26, L. fermentum I24 and C17, and L. brevis C10). Analysis of the plasmid profiles of these five cured derivatives revealed that all of the derivatives, except for L. acidophilus I16, possessed profiles similar to those of wild-type strains. The curing of L. acidophilus I16 was accompanied by the loss of 4.4 kb, 6.1 kb, and 11.5 kb plasmids.

Matched MeSH terms: Sodium Dodecyl Sulfate/pharmacology
Particle size analysis of nanocrystals: improved analysis method

Keck CM

Int J Pharm, 2010 May 5;390(1):3-12.
PMID: 19733647 DOI: 10.1016/j.ijpharm.2009.08.042

The influence of optical parameters, additional techniques (e.g. PIDS technology) and the importance of light microscopy were investigated by comparing laser diffraction data obtained via the conventional method and an optimized analysis method. Also the influence of a possible dissolution of nanocrystals during a measurement on the size result obtained was assessed in this study. The results reveal that dissolution occurs if unsaturated medium or microparticle saturated medium is used for the measurements. The dissolution is erratic and the results are not reproducible. Dissolution can be overcome by saturating the measuring medium prior to the measurement. If nanocrystals are analysed the dispersion medium should be saturated with the nanocrystals, because the solubility is higher than for coarse micro-sized drug material. The importance of using the optimized analysis method was proven by analysing 40 different nanosuspensions via the conventional versus the optimized sizing method. There was no large difference in the results obtained for the 40 nanosuspensions using the conventional method. This would have led to the conclusion, that all the 40 formulations investigated are physically stable. However, the analysis via the optimized method revealed that from 40 formulations investigated only four were physically stable. In conclusion an optimized analysis saves time and money and avoids misleading developments, because discrimination between "stable" and "unstable" can be done reliably at a very early stage of the development.

Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry
Fulltext Partial characterization of an enzymatic extract from Bentong ginger (Zingiber officinale var. Bentong)

Nafi' A, Ling FH, Bakar J, Ghazali HM

Molecules, 2014 Aug 15;19(8):12336-48.
PMID: 25153861 DOI: 10.3390/molecules190812336

Extraction of protease from a local ginger rhizome (Zingiber officinale var. Bentong) was carried out. The effect of extraction pH (6.4, 6.8, 7.0, 7.2, 7.6, 8.0, 8.4, and 8.8) and stabilizers (0.2% ascorbic acid, 0.2% ascorbic acid and 5 mM EDTA, or 10 mM cysteine and 5 mM EDTA) on protease activity during extraction was examined. pH 7.0 potassium phosphate buffer and 10 mM cysteine in combination with 5 mM EDTA as stabilizer were found to be the most effective conditions. The extraction procedure yielded 0.73% of Bentong ginger protease (BGP) with a specific activity of 24.8±0.2 U/mg protein. Inhibitory tests with some protease inhibitors classified the enzyme as a cysteine protease. The protease showed optimum activity at 60 °C and pH 6-8, respectively. The enzyme was completely inhibited by heavy metal cations such as Cu2+, and Hg2+. SDS stimulated the activity of enzyme, while emulsifiers (Tween 80 and Tween 20) slightly reduced its activity. The kinetic analysis showed that the protease has Km and Vmax values of 0.21 mg mL-1 and 34.48 mg mL-1 min-1, respectively. The dried enzyme retained its activity for 22 months when stored at -20 °C.

Matched MeSH terms: Sodium Dodecyl Sulfate/chemistry
Fulltext PREPARATION AND CHARACTERIZATION OF MAGNESIUM/ALUMINIUM LAYERED DOUBLE HYDROXIDE AS FILLER IN LOW-DENSITY POLYETHYLENE COMPOSITE

NUR ATHIRAH ZULKIFLI, MOHD AIDIL ADHHA ABDULLAH, MAZIDAH MAMAT

UMT Journal of Undergraduate Research, 2021;3(1):1-6.
MyJurnal

Polymer had been widely used in industries nowadays. However, the properties of the polymer itself are limited to a particular application. This study describes synthetic clay, layered double hydroxide (LDH), as a filler in low-density polyethylene (LDPE) composite. LDHs of magnesium/aluminium-dodecyl sulfate (Mg/Al-DS) and its grafted with triethoxymethylsilane (TEMS), (TEMS-g-Mg/Al-DS) were synthesized through co-precipitation and salinization reaction methods. The presence of alkyl group, v(C-H) in both LDH had confirmed through Fourier transform infrared (FTIR). The appearance of peaks in FTIR spectra within the absorbance range of 2800 – 2930 cm-1indicates a successful surface modification of LDH, supported by the changes of interlayer spacing and the presence of carbon from X-ray diffractogram and CHNS elemental analysis, respectively. The synthesized LDH was mixed with LDPE via melt intercalation method. The LDH modification resulted in higher interaction and compatibility between the LDPE matrix and LDH by the formation exfoliated type of nanocomposites, as suggested by XRD analysis.

Matched MeSH terms: Sodium Dodecyl Sulfate

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