101
|
Nuchtavorn N, Dvořák M, Kubáň P. Paper-based molecularly imprinted-interpenetrating polymer network for on-spot collection and microextraction of dried blood spots for capillary electrophoresis determination of carbamazepine. Anal Bioanal Chem 2020; 412:2721-2730. [DOI: 10.1007/s00216-020-02523-w] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2019] [Revised: 02/07/2020] [Accepted: 02/14/2020] [Indexed: 12/11/2022]
|
102
|
Näsström T, Ådén J, Shibata F, Andersson PO, Karlsson BC. A Capped Peptide of the Aggregation Prone NAC 71-82 Amino Acid Stretch of α-Synuclein Folds into Soluble β-Sheet Oligomers at Low and Elevated Peptide Concentrations. Int J Mol Sci 2020; 21:ijms21051629. [PMID: 32120928 PMCID: PMC7084662 DOI: 10.3390/ijms21051629] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2019] [Revised: 02/25/2020] [Accepted: 02/25/2020] [Indexed: 12/13/2022] Open
Abstract
Although Lewy bodies and Lewy neurites are hallmarks of Parkinson's disease (PD) and dementia with Lewy bodies (DLB), misfolded α-synuclein oligomers are nowadays believed to be key for the development of these diseases. Attempts to target soluble misfolded species of the full-length protein have been limited so far, probably due to the fast aggregation kinetics and burial of aggregation prone segments in final cross-β-sheet fibrils. A previous characterisation study of fibrils prepared from a capped peptide of the non-amyloid β-component (NAC) 71-82 amino acid stretch of α-synuclein demonstrated an increased aggregation propensity resulting in a cross-β-structure that is also found in prion proteins. From this, it was suggested that capped NAC 71-82 peptide oligomers would provide interesting motifs with a capacity to regulate disease development. Here, we demonstrated, from a series of circular dichroism spectroscopic measurements and molecular dynamics simulations, the molecular-environment-sensitive behaviour of the capped NAC 71-82 peptide in a solution phase and the formation of β-sheet oligomeric structures in the supernatant of a fibrillisation mixture. These results highlighted the use of the capped NAC 71-82 peptide as a motif in the preparation of oligomeric β-sheet structures that potentially could be used in therapeutic strategies in the fight against progressive neurodegenerative disorders, such as PD and DLB.
Collapse
Affiliation(s)
- Thomas Näsström
- Physical Pharmacy Laboratory, Linnaeus University Centre for Biomaterials Chemistry, Linnaeus University, SE-392 31 Kalmar, Sweden;
- Correspondence: (T.N.); (B.C.G.K.); Tel.: +46-480-446329 (T.N.); +46-480-446740 (B.C.G.K.)
| | - Jörgen Ådén
- Department of Chemistry, University of Umeå, SE-901 87 Umeå, Sweden;
| | - Fumina Shibata
- Physical Pharmacy Laboratory, Linnaeus University Centre for Biomaterials Chemistry, Linnaeus University, SE-392 31 Kalmar, Sweden;
| | - Per Ola Andersson
- Department of Engineering Sciences: Applied Material Science, Uppsala University, SE-751 21 Uppsala, Sweden;
| | - Björn C.G. Karlsson
- Physical Pharmacy Laboratory, Linnaeus University Centre for Biomaterials Chemistry, Linnaeus University, SE-392 31 Kalmar, Sweden;
- Correspondence: (T.N.); (B.C.G.K.); Tel.: +46-480-446329 (T.N.); +46-480-446740 (B.C.G.K.)
| |
Collapse
|
103
|
Amin MR, Alissa SA, Molla MR, Rub MA, Wabaidur SM, Hoque MA, Kabir SE. Influence of the effect of different electrolytes on the interaction of promethazine hydrochloride drug with tetradecyltrimethylammonium bromide at different temperatures. J PHYS ORG CHEM 2020. [DOI: 10.1002/poc.4057] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Affiliation(s)
- Md. Ruhul Amin
- Department of ChemistryJahangirnagar University Dhaka Bangladesh
| | - Siham A. Alissa
- Chemistry Department, College of SciencePrincess Nourah bint Abdulrahman University Riyadh Saudi Arabia
| | - Mohammad Robel Molla
- Department of ChemistryJahangirnagar University Dhaka Bangladesh
- Industrial Physics DivisionBCSIR Laboratories Dhaka Bangladesh
| | - Malik Abdul Rub
- Chemistry Department, Faculty of ScienceKing Abdulaziz University Jeddah Saudi Arabia
| | | | - Md. Anamul Hoque
- Department of ChemistryJahangirnagar University Dhaka Bangladesh
| | - Shariff E. Kabir
- Department of ChemistryJahangirnagar University Dhaka Bangladesh
| |
Collapse
|
104
|
Study of surface properties of aqueous solutions of sodium dodecyl sulfate in the presence of hydrochloric acid and heavy metal ions. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112170] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
105
|
Jacumazo J, de Carvalho MM, Parchen GP, Campos IM, Ballesteros Garcia MJ, Brugnari T, Maciel GM, Marques FA, de Freitas RA. Development, characterization and antimicrobial activity of sodium dodecyl sulfate-polysaccharides capsules containing eugenol. Carbohydr Polym 2020; 230:115562. [PMID: 31887918 DOI: 10.1016/j.carbpol.2019.115562] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/17/2019] [Accepted: 10/31/2019] [Indexed: 11/24/2022]
|
106
|
Ishtikhar M, Siddiqui Z, Husain FM, Khan RA, Hassan I. Comparative refolding of guanidinium hydrochloride denatured bovine serum albumin assisted by cationic and anionic surfactants via artificial chaperone protocol: Biophysical insight. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2020; 225:117510. [PMID: 31520999 DOI: 10.1016/j.saa.2019.117510] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 08/28/2019] [Accepted: 09/03/2019] [Indexed: 06/10/2023]
Abstract
In the present study, we report the cooperative refolding/renaturation behaviour of guanidinium hydrochloride (GdnHCl) denatured bovine serum albumin (BSA) in the presence of cationic surfactant cetyltrimethylammonium bromide (CTAB), anionic surfactant sodium dodecyl sulphate (SDS) and their catanionic mixture in the solution of 60 mM sodium phosphate buffer of physiological pH 7.4, using artificial chaperone-assisted two-step method. Here, we have employed biophysical techniques to characterize the refolding mechanism of denatured BSA after 200 times of dilution in the presence of cationic, anionic surfactants and their catanionic mixture, separately. We have found that minimum refolding of diluted BSA in the presence of 1:1 rational mixture of CTAB and SDS (CTAB/SDS = 50/50), it may be due to the micelles formation which is responsible for the unordered microstructure aggregate formation. Other mixtures (CTAB/SDS = 20/80 and 80/20) slightly played an effective role during refolding process in the presence of methyl-β-cyclodextrin. On other hand, CTAB and SDS are more effective and reflect a good renaturation tendency of denatured BSA solution separately and in existence of methyl-β-cyclodextrin as compare to their mixture compositions. But overall, CTAB has the better renaturation tendency as compare to SDS in the existence of methyl-β-cyclodextrin. These results ascribed the presence of charge head group and length of hydrophobic tail of CTAB surfactant that plays an important task during electrostatic and hydrophobic interactions at pH 7.4 at which BSA carries negative charge on their surface. These biophysical parameters suggest that, CTAB surfactant assisted artificial chaperone protocol may be utilized in the protein renaturation/refolding studies, which may address the associated problems of biotechnological industries for the development of efficient and inexpensive folding aides, which may also be used to produced genetically engineered cells related diseases, resulting from protein misfolding/aggregation.
Collapse
Affiliation(s)
- Mohd Ishtikhar
- Department of Chemistry, Indian Institute of Technology Bombay, Powai, Mumbai 400076, India.
| | - Zeba Siddiqui
- Department of Biosciences, Integral University, Lucknow 226026, India
| | - Fohad Mabood Husain
- Department of Food Science and Nutrition, College of Food and Agricultural Sciences, King Saud University, 2460, Riyadh 11451, Saudi Arabia
| | - Rais Ahmad Khan
- Department of Chemistry, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| | - Iftekhar Hassan
- Department of Zoology, College of Science, King Saud University, P.O. Box 2455, Riyadh 11451, Saudi Arabia
| |
Collapse
|
107
|
Nguyen D, Zhu L, Huynh VT, Azniwati AA, Pham NTH, Lam MT, Serelis AK, Davey T, Such C, Neto C, Hawkett BS. Soft–hard Janus nanoparticles for polymer encapsulation of solid particulate. Polym Chem 2020. [DOI: 10.1039/d0py00845a] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Janus nanoparticles with soft lobes can self-assemble on the surface of solid substrates in aqueous phase and coalesce to form a complete polymer shell encapsulating the entire solid substrate.
Collapse
|
108
|
Schlüter F, Bela MM, Glikman D, Braunschweig B, Ravoo BJ. A cyclodextrin surfactant for stable emulsions with an accessible cavity for host–guest complexation. Chem Commun (Camb) 2020; 56:15434-15437. [DOI: 10.1039/d0cc06657e] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Oil-in-water-emulsions stabilized by an anionic β-cyclodextrin surfactant show long term stability and accessibility of the cavity for host–guest-complexation.
Collapse
Affiliation(s)
- Friederike Schlüter
- Center for Soft Nanoscience (SoN)
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
- Organic Chemistry Institute
| | - Marlena M. Bela
- Center for Soft Nanoscience (SoN)
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
- Organic Chemistry Institute
| | - Dana Glikman
- Center for Soft Nanoscience (SoN)
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
- Institute of Physical Chemistry
| | - Björn Braunschweig
- Center for Soft Nanoscience (SoN)
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
- Institute of Physical Chemistry
| | - Bart Jan Ravoo
- Center for Soft Nanoscience (SoN)
- Westfälische Wilhelms-Universität Münster
- 48149 Münster
- Germany
- Organic Chemistry Institute
| |
Collapse
|
109
|
Jora MZ, de Souza RN, Barbosa TM, Tormena CF, Sabadini E. Probing the Formation of Wormlike Micelles Formed by Cationic Surfactant with Chlorobenzoate Derivatives. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:17046-17053. [PMID: 31809055 DOI: 10.1021/acs.langmuir.9b02173] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
The energy released when tetradecyltrimethylammonium bromide (C14TAB) is combined with different derivatives of chlorobenzoates in an isothermal titration calorimeter (ITC) allows a direct evaluation of the spontaneity of the threading of the aromatic anions into the micellar palisade. The comparison between the enthalpimetric curves with the ones for viscosity of the solutions, hydrodynamic radii of the aggregates (dynamic light scattering experiments), and the fraction of aromatic anions incorporated (diffusion-ordered spectroscopy experiments) allows the establishment of the variations of enthalpy with formation, growth, and decrease of the wormlike micelles (WLMs). The formation of WLMs with C14TAB is very favored (very exothermic) for titrations of chlorobenzoate derivatives which present the chlorine atom in positions 3 or 4 of the aromatic ring. However, the aggregation is highly unfavorable if chlorine is at position 2 of chlorobenzoate. According to the results, the high potential of the ITC to determine critical concentrations and the energies associated with the aggregation of a cationic surfactant and aromatic anions for the formation of WLMs was demonstrated.
Collapse
Affiliation(s)
- Manazael Z Jora
- Physical Chemistry Department, Institute of Chemistry , University of Campinas-UNICAMP . P.O. Box 6154, 13084-862 Campinas , São Paulo , Brazil
| | - Renato N de Souza
- Physical Chemistry Department, Institute of Chemistry , University of Campinas-UNICAMP . P.O. Box 6154, 13084-862 Campinas , São Paulo , Brazil
| | - Thaís M Barbosa
- Organic Chemistry Department, Institute of Chemistry , University of Campinas-UNICAMP , P.O. Box: 6154, 13083-970 Campinas , São Paulo , Brazil
| | - Cláudio F Tormena
- Organic Chemistry Department, Institute of Chemistry , University of Campinas-UNICAMP , P.O. Box: 6154, 13083-970 Campinas , São Paulo , Brazil
| | - Edvaldo Sabadini
- Physical Chemistry Department, Institute of Chemistry , University of Campinas-UNICAMP . P.O. Box 6154, 13084-862 Campinas , São Paulo , Brazil
| |
Collapse
|
110
|
Hermet M, Bakás L, Morcelle SR, Bernik DL. Bromide counterion as a spectroscopic sensor at the interface of cetyltrimethylammonium micelles. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 2019; 223:117266. [PMID: 31260887 DOI: 10.1016/j.saa.2019.117266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/12/2019] [Revised: 05/31/2019] [Accepted: 06/09/2019] [Indexed: 06/09/2023]
Abstract
The strong UV absorption of the bromide in aqueous solution undergoes a remarkable red shift of more than 10 nm induced by the addition of the salts that constitute a saline buffer. The maximum absorption wavelength of the bromide is displaced from approximately 194 nm in ultrapure water to wavelengths above 200 nm, depending on the composition of the solution. The bromide spectrum as counterion of the cetyltrimethylammonium in the surfactant CTAB also shows sensitivity to the aggregation behavior of the tensioactive, being able to detect intermolecular interactions even at concentrations lower than the critical micelle concentration. And, when the micelles are assembled, the bromide absorption detects the interfacial rearrangements caused by the incorporation of ions. To know more about those interfacial features, the pyrene molecular probe was used, taking advantage of the extensive knowledge of its spectroscopy. Pyrene verifies the existence of changes in the interfacial organization which confirm that the sensitivity of the bromide spectrum is based on the ability of the ion to detect its microenvironment, and therefore reaffirms that its absorption spectrum can be used as a local sensor. The present work encourages the use of bromide as a sensor ion in the UV region between 190 and 210 nm, which would avoid the introduction of external molecular probes that could disturb the system.
Collapse
Affiliation(s)
- Melisa Hermet
- Plant Proteins Research Center (CIProVe), National University of La Plata, Calles 47 y 115, CP1900, La Plata, Buenos Aires, Argentina
| | - Laura Bakás
- Plant Proteins Research Center (CIProVe), National University of La Plata, Calles 47 y 115, CP1900, La Plata, Buenos Aires, Argentina
| | - Susana R Morcelle
- Plant Proteins Research Center (CIProVe), National University of La Plata, Calles 47 y 115, CP1900, La Plata, Buenos Aires, Argentina
| | - Delia L Bernik
- Plant Proteins Research Center (CIProVe), National University of La Plata, Calles 47 y 115, CP1900, La Plata, Buenos Aires, Argentina.
| |
Collapse
|
111
|
Fernández-Pumarega A, Amézqueta S, Fuguet E, Rosés M. Determination of the retention factor of ionizable compounds in microemulsion electrokinetic chromatography. Anal Chim Acta 2019; 1078:221-230. [DOI: 10.1016/j.aca.2019.06.007] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2019] [Revised: 05/30/2019] [Accepted: 06/02/2019] [Indexed: 10/26/2022]
|
112
|
Zheng Q, Ayala AX, Chung I, Weigel AV, Ranjan A, Falco N, Grimm JB, Tkachuk AN, Wu C, Lippincott-Schwartz J, Singer RH, Lavis LD. Rational Design of Fluorogenic and Spontaneously Blinking Labels for Super-Resolution Imaging. ACS CENTRAL SCIENCE 2019; 5:1602-1613. [PMID: 31572787 PMCID: PMC6764213 DOI: 10.1021/acscentsci.9b00676] [Citation(s) in RCA: 127] [Impact Index Per Article: 25.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Indexed: 05/24/2023]
Abstract
Rhodamine dyes exist in equilibrium between a fluorescent zwitterion and a nonfluorescent lactone. Tuning this equilibrium toward the nonfluorescent lactone form can improve cell-permeability and allow creation of "fluorogenic" compounds-ligands that shift to the fluorescent zwitterion upon binding a biomolecular target. An archetype fluorogenic dye is the far-red tetramethyl-Si-rhodamine (SiR), which has been used to create exceptionally useful labels for advanced microscopy. Here, we develop a quantitative framework for the development of new fluorogenic dyes, determining that the lactone-zwitterion equilibrium constant (K L-Z) is sufficient to predict fluorogenicity. This rubric emerged from our analysis of known fluorophores and yielded new fluorescent and fluorogenic labels with improved performance in cellular imaging experiments. We then designed a novel fluorophore-Janelia Fluor 526 (JF526)-with SiR-like properties but shorter fluorescence excitation and emission wavelengths. JF526 is a versatile scaffold for fluorogenic probes including ligands for self-labeling tags, stains for endogenous structures, and spontaneously blinking labels for super-resolution immunofluorescence. JF526 constitutes a new label for advanced microscopy experiments, and our quantitative framework will enable the rational design of other fluorogenic probes for bioimaging.
Collapse
Affiliation(s)
- Qinsi Zheng
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Anthony X. Ayala
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Inhee Chung
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Aubrey V. Weigel
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Anand Ranjan
- Department of Biology and Department of Molecular
Biology and Genetics, Johns Hopkins University, Baltimore,
Maryland 21218, United States
| | - Natalie Falco
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Jonathan B. Grimm
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Ariana N. Tkachuk
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| | - Carl Wu
- Department of Biology and Department of Molecular
Biology and Genetics, Johns Hopkins University, Baltimore,
Maryland 21218, United States
| | | | - Robert H. Singer
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
- Department of Anatomy and Structural Biology,
Albert Einstein College of Medicine, Bronx, New York 10461,
United States
| | - Luke D. Lavis
- Janelia Research Campus, Howard Hughes
Medical Institute, Ashburn, Virginia 20147, United
States
| |
Collapse
|
113
|
Chakraborty S, Kahan TF. Emerging investigator series: spatial distribution of dissolved organic matter in ice and at air-ice interfaces. ENVIRONMENTAL SCIENCE. PROCESSES & IMPACTS 2019; 21:1076-1084. [PMID: 31241094 DOI: 10.1039/c9em00190e] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Dissolved organic matter (DOM) is a common solute in snow and ice at Earth's surface. Its effects on reaction kinetics in ice and at air-ice interfaces can be large, but are currently difficult to quantify. We used Raman microscopy to characterize the surface and bulk of frozen aqueous solutions containing humic acid, sodium dodecyl sulfate (SDS), and citric acid at a range of concentrations and temperatures. The surface-active species (humic acid and SDS) were distributed differently than citric acid. Humic acid and SDS are almost completely excluded to the air-ice interface during freezing, where they form a film that coats the surface nearly completely. A liquid layer that coats the majority of the surface was observed at all humic acid and SDS concentrations. Citric acid, which is smaller and less surface active, is excluded to liquid channels at the air-ice interface and within the ice bulk, as has previously been reported for ionic solutes such as sodium chloride. Incomplete surface wetting was observed at all citric acid concentrations and at all temperatures (up to -5 °C). Citric acid appears to be solvated in frozen samples, but SDS and humic acid do not. These results will improve our understanding of the effects of organic solutes on environmental and atmospheric chemistry within ice and at air-ice interfaces.
Collapse
Affiliation(s)
- Subha Chakraborty
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada. and Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, NY 13244, USA
| | - Tara F Kahan
- Department of Chemistry, University of Saskatchewan, 110 Science Place, Saskatoon, SK S7N 5C9, Canada. and Department of Chemistry, Syracuse University, 1-014 Center for Science and Technology, Syracuse, NY 13244, USA
| |
Collapse
|
114
|
Holínková P, Pekař M. Fluorescence Study of Aggregation Behaviour of Cationic Surfactant Carbethopendecinium Bromide and its Comparison with Cetyltrimethylammonium Bromide. TENSIDE SURFACT DET 2019. [DOI: 10.3139/113.110633] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Abstract
The aggregation behaviour of the cationic surfactant carbethopendecinium bromide (Septonex) and cetyltrimethylammonium bromide (CTAB) in aqueous solution was investigated by steady-state and time-resolved fluorescence experiments. Values of critical micelle concentration were obtained from the pyrene emission polarity index. The micellar aggregation numbers for four different concentrations of both surfactants were determined by steady-state and time-resolved fluorescence quenching methods, using pyrene as a probe and cetylpyridinium chloride as a quencher. The results obtained for Septonex were compared with the aggregation parameters of CTAB. Generally, Septonex micelles were formed by a smaller number of surfactant monomers than in the case of CTAB and the critical micelle concentration of Septonex is lower than that of CTAB. Also, the concentration dependence of the micelle aggregation number was found.
Collapse
Affiliation(s)
- Petra Holínková
- Materials Research Centre , Faculty of Chemistry, Brno University of Technology, Brno , Czech Republic
| | - Miloslav Pekař
- Materials Research Centre , Faculty of Chemistry, Brno University of Technology, Brno , Czech Republic
| |
Collapse
|
115
|
Khan JM, Ahmed A, Freeh Alamery S, Farah MA, Hussain T, Khan MI, Khan RH, Malik A, Fatima S, Sen P. Millimolar concentration of sodium dodecyl sulfate inhibit thermal aggregation in hen egg white lysozyme via increased α-helicity. Colloids Surf A Physicochem Eng Asp 2019. [DOI: 10.1016/j.colsurfa.2019.03.085] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|
116
|
Berzina B, Anand RK. Continuous micellar electrokinetic focusing of neutral species driven by ion concentration polarization. LAB ON A CHIP 2019; 19:2233-2240. [PMID: 31161167 DOI: 10.1039/c9lc00327d] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Ion concentration polarization (ICP) has been broadly applied to accomplish electrokinetic focusing of charged species. However, ICP-based extraction and enrichment of uncharged (neutral) compounds, important for pharmaceutical, biological, and environmental applications, has not yet been reported. Here, we report the ICP-based continuous extraction of two neutral compounds from aqueous solution, by their partition into an ionic micellar phase. Our initial results show that the efficiency of the extraction increases with the concentration of the surfactant comprising the micellar phase, reaching 98 ± 2%, and drops precipitously when the concentration of the target compound exceeds the capacity of the micelles. As a key feature relevant to the practical application of this method, we show that focusing occurs even an order of magnitude below the critical micelle concentration through the local enrichment and assembly of surfactants into micelles, thus minimizing their consumption. To underscore the relevance of this approach to water purification, this method is applied to the extraction of pyrene, a model for polyaromatic hydrocarbons. This approach provides access to a broad range of strategies for selective separation that have been developed in micellar electrokinetic chromatography.
Collapse
Affiliation(s)
- Beatrise Berzina
- The Department of Chemistry, Iowa State University, 2415 Osborn Drive, 1605 Gilman Hall, Ames, Iowa 50011-1021, USA.
| | | |
Collapse
|
117
|
Socia A, Liu Y, Abend A, Wuelfing WP. Mechanistic understanding of abnormal reverse phase chromatographic behavior of basic analytes in the presence of sodium dodecyl sulfate. J Chromatogr A 2019; 1595:108-116. [DOI: 10.1016/j.chroma.2019.02.044] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2018] [Revised: 02/17/2019] [Accepted: 02/20/2019] [Indexed: 10/27/2022]
|
118
|
Song Y, Xu B, Yuan Y, Xu H, Li D. Coalescence of a Water Drop with an Air-Liquid Interface: Electric Current Generation and Critical Micelle Concentration (CMC) Sensing Application. ACS APPLIED MATERIALS & INTERFACES 2019; 11:16981-16990. [PMID: 30933464 DOI: 10.1021/acsami.9b00365] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
A phenomenon that electric current is generated when a pendant water droplet touches an air-electrolyte solution interface is investigated in this paper. A measurement system developed in this study consists of a hollow electrode for droplet generation, a counter electrode immersed in an electrolyte solution, and an electrometer with high precision. Once a droplet touches the air-electrolyte solution interface, it will be pulled into the electrolyte solution and an electric current is produced during this process. Experiments showed that the magnitude of the electric current depends only on the pendant droplet and has nothing to do with the types of the electrolyte solution (with a much larger volume than that of the droplet) below the drop. The electric current is generated by the electric potential difference between the droplet and air-electrolyte solution interface and the liquid bridge formed during droplet coalescence. As a result, the magnitude of the generated electrical current mainly depends on the size, pH, and the type of the solution forming the droplet. Determining the critical micelle concentration using this system was successfully achieved to show the powerfulness of this system.
Collapse
Affiliation(s)
- Yongxin Song
- Department of Marine Engineering , Dalian Maritime University , Dalian 116026 , China
| | - Bin Xu
- Department of Marine Engineering , Dalian Maritime University , Dalian 116026 , China
| | - Yapeng Yuan
- Department of Marine Engineering , Dalian Maritime University , Dalian 116026 , China
| | - Hao Xu
- Department of Marine Engineering , Dalian Maritime University , Dalian 116026 , China
| | - Dongqing Li
- Department of Mechanical and Mechatronics Engineering , University of Waterloo , Waterloo , ON N2L 3G1 , Canada
| |
Collapse
|
119
|
Húmpola MV, Rey MC, Spontón PG, Simonetta AC, Tonarelli GG. A Comparative Study of the Antimicrobial and Structural Properties of Short Peptides and Lipopeptides Containing a Repetitive Motif KLFK. Protein Pept Lett 2019; 26:192-203. [PMID: 30526450 DOI: 10.2174/0929866526666181208144629] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2018] [Revised: 11/16/2018] [Accepted: 12/04/2018] [Indexed: 11/22/2022]
Abstract
BACKGROUND In the last years, Antimicrobial Peptides (AMPs) and lipopeptides have received attention as promising candidates to treat infections caused by resistant microorganisms. OBJECTIVE The main objective of this study was to investigate the effect of repetitive KLFK motifs and the attachment of aliphatic acids to the N-terminus of (KLFK)n peptides on therapeutic properties. METHODS Minimal inhibitory concentration against Gram (+) and (-) bacteria and yeast of synthetic compounds were determined by broth microtiter dilution method, and the toxicity was evaluated by hemolysis assay. Membrane-peptide interaction studies were performed with model phospholipid membranes mimicking those of bacterial and mammalian cells by Fluorescence Spectroscopy. The secondary structure in solution and membranes was determined by Circular Dichroism. RESULTS Our results showed that the resulting compounds have inhibitory activity against bacteria and fungi. The (KLFK)3 peptide showed the highest therapeutic index against bacterial and yeast strains, and the (KLFK)2 peptide conjugated with octanoic acid was the most active against yeasts. All the lipopeptides containing long-chain fatty acids (C14 or longer) were highly hemolytic at low concentrations. The antimicrobial activity of (KLFK)2 and (KLFK)3 lipopeptides was mainly associated with improved stability of the amphipathic secondary structure, which showed high contributions of α-helix in dipalmitoylphosphatidylglycerol (DPPG) vesicles. CONCLUSION The repetition of the KLFK sequence and the conjugation with lipid tails allowed obtained compounds with high antimicrobial activity and low toxicity, becoming good candidates for treating infectious diseases.
Collapse
Affiliation(s)
- María Verónica Húmpola
- Departamento de Quimica Organica, Facultad de Bioquimica y Cs. Biologicas, Universidad Nacional del Litoral (U.N.L), Santa Fe, Argentina
| | - María Carolina Rey
- Departamento de Quimica Organica, Facultad de Bioquimica y Cs. Biologicas, Universidad Nacional del Litoral (U.N.L), Santa Fe, Argentina
| | - Pablo Gabriel Spontón
- Departamento de Quimica Organica, Facultad de Bioquimica y Cs. Biologicas, Universidad Nacional del Litoral (U.N.L), Santa Fe, Argentina.,Catedras de Microbiologia y Biotecnologia, Departamento de Ingenieria en Alimentos, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Arturo Carlos Simonetta
- Catedras de Microbiologia y Biotecnologia, Departamento de Ingenieria en Alimentos, Facultad de Ingenieria Quimica, Universidad Nacional del Litoral, Santa Fe, Argentina
| | - Georgina Guadalupe Tonarelli
- Departamento de Quimica Organica, Facultad de Bioquimica y Cs. Biologicas, Universidad Nacional del Litoral (U.N.L), Santa Fe, Argentina
| |
Collapse
|
120
|
Khan H, Seddon JM, Law RV, Brooks NJ, Robles E, Cabral JT, Ces O. Effect of glycerol with sodium chloride on the Krafft point of sodium dodecyl sulfate using surface tension. J Colloid Interface Sci 2019; 538:75-82. [DOI: 10.1016/j.jcis.2018.11.021] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Revised: 11/02/2018] [Accepted: 11/07/2018] [Indexed: 10/27/2022]
|
121
|
Hu TM, Chou HC, Lin CY. Facile green synthesis of organosilica nanoparticles by a generic “salt route”. J Colloid Interface Sci 2019; 539:634-645. [DOI: 10.1016/j.jcis.2018.12.080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2018] [Revised: 12/04/2018] [Accepted: 12/20/2018] [Indexed: 10/27/2022]
|
122
|
Klass SH, Smith MJ, Fiala TA, Lee JP, Omole AO, Han BG, Downing KH, Kumar S, Francis MB. Self-Assembling Micelles Based on an Intrinsically Disordered Protein Domain. J Am Chem Soc 2019; 141:4291-4299. [DOI: 10.1021/jacs.8b10688] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Affiliation(s)
- Sarah H. Klass
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Matthew J. Smith
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Tahoe A. Fiala
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Jess P. Lee
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | - Anthony O. Omole
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| | | | | | - Sanjay Kumar
- Department of Bioengineering, University of California, Berkeley, California 94720, United States
| | - Matthew B. Francis
- Department of Chemistry, University of California, Berkeley, California 94720, United States
| |
Collapse
|
123
|
Răducan A, Puiu M, Oancea P, Colbea C, Velea A, Dinu B, Mihăilescu AM, Galaon T. Fast decolourization of Indigo Carmine and Crystal Violet in aqueous environments through micellar catalysis. Sep Purif Technol 2019. [DOI: 10.1016/j.seppur.2018.08.052] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
124
|
Gebeyehu BT, Lee AW, Huang SY, Muhabie AA, Lai JY, Lee DJ, Cheng CC. Highly stable photosensitive supramolecular micelles for tunable, efficient controlled drug release. Eur Polym J 2019. [DOI: 10.1016/j.eurpolymj.2018.12.005] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
|
125
|
Das T, Eliezer D. Probing Structural Changes in Alpha-Synuclein by Nuclear Magnetic Resonance Spectroscopy. Methods Mol Biol 2019; 1948:157-181. [PMID: 30771177 PMCID: PMC8193918 DOI: 10.1007/978-1-4939-9124-2_13] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Alpha-synuclein, the principal protein involved in the pathogenesis of Parkinson's disease, has been shown to exchange between multiple conformational states, with hitherto unclear physiological role of such conformational changes. Due to its ability to provide rich structural information for proteins in their near-native environment, nuclear magnetic resonance (NMR) spectroscopy has been a valuable tool to study these conformational states. In this review we describe the application of model systems and NMR methods to the study of membrane-bound states of alpha-synuclein. We provide a detailed description, primarily meant for someone new to the field, of how to prepare the necessary samples, perform the basic experiments, and obtain an initial interpretation of the results.
Collapse
|
126
|
Abedi S, Suteria NS, Chen CC, Vanapalli SA. Microfluidic production of size-tunable hexadecane-in-water emulsions: Effect of droplet size on destabilization of two-dimensional emulsions due to partial coalescence. J Colloid Interface Sci 2019; 533:59-70. [DOI: 10.1016/j.jcis.2018.08.045] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 08/15/2018] [Accepted: 08/16/2018] [Indexed: 11/16/2022]
|
127
|
Chauhan S, Sharma V, Singh K, Chauhan M. Effect of Maltodextrin and Temperature on Micellar Behavior of Bile Salts in Aqueous Medium: Conductometric and Spectrofluorimetric Studies. Z PHYS CHEM 2018. [DOI: 10.1515/zpch-2017-1060] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
Abstract
Conductivity and fluorescence probe techniques have been employed to study the micellar behavior of bile salts i.e. sodium cholate (1–20 mmol⋅kg−1) and sodium deoxycholate (0.5–10.0 mmol⋅kg−1) in aqueous solutions of maltodextrin (0.0, 0.5, 1.1, and 1.6 mmol⋅kg−1) at different temperatures. The influence of maltodextrin on the micellization behavior of bile salts has been determined in terms of critical micelle concentration (CMC) values obtained from conductivity measurement. The variation in CMC values has been discussed by considering the alteration in the hydrophobic environment of maltodextrin-sodium cholate/sodium deoxycholate complex imparted by the carbohydrate molecules. In order to substantiate the CMC values determined from conductivity method, the fluorescence probe study of aqueous sodium cholate and sodium deoxycholate solutions in presence of fluorescent, pyrene has also been carried. The CMC values obtained from both techniques are in full agreement with each other. Moreover, application of charged pseudo-phase separation model has been made to discuss the thermodynamics of the system.
Collapse
Affiliation(s)
- Suvarcha Chauhan
- Department of Chemistry , Himachal Pradesh University , Summer Hill, Shimla 171005 , India , Tel.: +91 177 2830803, fax: +91 177 2830775
| | - Vivek Sharma
- Department of Chemistry , Himachal Pradesh University , Summer Hill, Shimla 171005 , India
| | - Kuldeep Singh
- Department of Chemistry , Himachal Pradesh University , Summer Hill, Shimla 171005 , India
| | - M.S. Chauhan
- Department of Chemistry , Himachal Pradesh University , Summer Hill, Shimla 171005 , India
| |
Collapse
|
128
|
Váňová J, Vavříková M, Smetanová Z, Česla P. Comparison of Electrophoretic Methods for Determination of Critical Micelle Concentration of Anionic Alkylsulfate Surfactants in Water/Organic Environment. Chromatographia 2018. [DOI: 10.1007/s10337-018-3664-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
129
|
Guo Y, Wang C, Dun J, Du L, Hawley M, Sun CC. Mechanism for the Reduced Dissolution of Ritonavir Tablets by Sodium Lauryl Sulfate. J Pharm Sci 2018; 108:516-524. [PMID: 30389564 DOI: 10.1016/j.xphs.2018.10.047] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2018] [Revised: 09/28/2018] [Accepted: 10/22/2018] [Indexed: 11/29/2022]
Abstract
Sodium lauryl sulfate (SLS) is an anionic surfactant widely used in pharmaceutical research as a dissolution enhancer for poorly soluble drugs. When SLS was used in ritonavir (RTV) tablet formulation to improve wetting, dissolution of RTV was surprisingly deteriorated in acidic media. To understand this unexpected phenomenon, a systematic investigation, including solubility determination, intrinsic dissolution rate measurement, dissolution in an artificial stomach and duodenum apparatus, and solid-state characterization, revealed the formation of a poorly soluble salt, [RTV2+][LS-]2, in an acidic environment. Solubilization of the poorly soluble RTV salt was observed when the concentration of SLS exceeded the critical micelle concentration. Thus, precipitation of [RTV2+][LS-]2 at a low pH and in presence of a low SLS concentration can lead to deteriorated bioavailability. This unintended negative effect on dissolution should be carefully considered when using SLS in a tablet formulation of a basic drug that can be ionized in gastric fluid.
Collapse
Affiliation(s)
- Yiwang Guo
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, S.E. Minneapolis, Minnesota 55455
| | - Chenguang Wang
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, S.E. Minneapolis, Minnesota 55455
| | - Jiangnan Dun
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, S.E. Minneapolis, Minnesota 55455
| | - Liying Du
- Material & Analytical Sciences, Boehringer Ingelheim, Ridgefield, Connecticut 06877
| | - Michael Hawley
- Material & Analytical Sciences, Boehringer Ingelheim, Ridgefield, Connecticut 06877
| | - Changquan Calvin Sun
- Department of Pharmaceutics, College of Pharmacy, University of Minnesota, S.E. Minneapolis, Minnesota 55455.
| |
Collapse
|
130
|
Miyabe K. Moment analysis for mass transfer kinetics at the interface of spherical molecular aggregates. J Chromatogr A 2018; 1572:172-178. [PMID: 30172357 DOI: 10.1016/j.chroma.2018.08.036] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 08/07/2018] [Accepted: 08/14/2018] [Indexed: 11/17/2022]
Abstract
New moment equations were developed on the basis of the principle of relativity for explaining some characteristics of elution peaks measured by electrokinetic chromatography (EKC) using spherical molecular aggregates. Basic equations representing mass balance and mass transfer kinetics in EKC system in a Galilean coordinate system S were transformed to those in another coordinate system S', which imaginarily moved with respect to S. Moment equations for EKC peaks in S' in the time domain were derived from the analytical solution of the modified basic equations in the Laplace domain. Moment equations for EKC peaks in S were derived from those in S' by the inverse Galilean transformation. The moment equations were used to the re-analysis of EKC data previously measured. The values of permeation rate constants of thymol at the interface of sodium dodecylsulfate micelles were fairly in agreement with those determined in a previous study. The moment equations were also used to the numerical simulation of elution peaks in EKC systems. The influence of some experimental parameters on elution peak profiles was quantitatively analyzed. The moment equations are useful for determining the rate constants of interfacial solute permeation from elution peak profiles measured by EKC.
Collapse
Affiliation(s)
- Kanji Miyabe
- Department of Chemistry, Faculty of Science, Rikkyo University, 3-34-1, Nishi-Ikebukuro, Toshima-ku, Tokyo, 171-8501, Japan.
| |
Collapse
|
131
|
Siposova K, Sedlak E, Kozar T, Nemergut M, Musatov A. Dual effect of non-ionic detergent Triton X-100 on insulin amyloid formation. Colloids Surf B Biointerfaces 2018; 173:709-718. [PMID: 30384267 DOI: 10.1016/j.colsurfb.2018.10.039] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2018] [Revised: 10/10/2018] [Accepted: 10/15/2018] [Indexed: 10/28/2022]
Abstract
Atomic force microscopy, Thioflavin T (ThT) fluorescence assay, circular dichroism spectroscopy, differential scanning calorimetry, and molecular modeling techniques have been employed to investigate the amyloid aggregation of insulin in the presence of non-ionic detergent, Triton X-100 (TX-100). In contrast to recently described inhibition of lysozyme amyloid formation by non-ionic detergents (Siposova, 2017), the amyloid aggregation of insulin in the presence of sub-micellar TX-100 concentration exhibits two dissimilar phases. The first, inhibition phase, is observed at the protein to detergent molar ratio of 1:0.1 to 1:1. During this phase, the insulin amyloid fibril formation is inhibited by TX-100 up to ∼60%. The second, "morphological" phase, is observed at increasing detergent concentration, corresponding to protein:detergent molar ratio of ∼1:1 - 1:10. Under these conditions a significant increase of the steady-state ThT fluorescence intensities and a dramatically changed morphology of the insulin fibrils were observed. Increasing of the detergent concentration above the CMC led to complete inhibition of amyloidogenesis. Analysis of the experimental and molecular modeling results suggests an existence of up to six TX-100 binding sites within dimer of insulin with different binding energy. The physiological relevance of the results is discussed.
Collapse
Affiliation(s)
- Katarina Siposova
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01, Kosice, Slovakia.
| | - Erik Sedlak
- Center for Interdisciplinary Biosciences, TIP - P.J. Safarik University, Jesenna 5, 041 54, Kosice, Slovakia
| | - Tibor Kozar
- Center for Interdisciplinary Biosciences, TIP - P.J. Safarik University, Jesenna 5, 041 54, Kosice, Slovakia; Laboratory of Information Technologies, Joint Institute for Nuclear Research, Joliot-Curie 6, 141980, Dubna, Moscow Region, Russia
| | - Michal Nemergut
- Department of Biophysics, Faculty of Science, P.J. Safarik University, Jesenna 5, 041 54, Kosice, Slovakia
| | - Andrey Musatov
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 040 01, Kosice, Slovakia
| |
Collapse
|
132
|
Drug partitioning in individual and mixed micelles and interaction with protein upon delivery form micellar media. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.05.107] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
|
133
|
Bitter S, Kunkel M, Burkart L, Mang A, Winter RF, Polarz S. Organometallic, Nonclassical Surfactant with Gemini Design Comprising π-Conjugated Constituents Ready for Modification. ACS OMEGA 2018; 3:8854-8864. [PMID: 30197995 PMCID: PMC6120738 DOI: 10.1021/acsomega.8b01405] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2018] [Accepted: 07/30/2018] [Indexed: 06/08/2023]
Abstract
Surfactants are functional molecules comprising a water-compatible head group and a hydrophobic tail. One of their features is the formation of self-assembled structures in contact with water, for instance, micelles, vesicles, or lyotropic liquid crystals. One way to increase the functionality of surfactants is to implement moieties containing transition-metal species. Ferrocene-based surfactants represent an excellent example because of the distinguished redox features. In most existing ferrocene-based amphiphiles, an alkyl chain is classically used as the hydrophobic tail. We report the synthesis and properties of 1-triisopropylsilylethynyl-1'-trimethylammoniummethylferrocene (FcNMe3TIPS). In FcNMe3TIPS, ferrocene is part of the head group (Gemini design) but is also attached to a (protected) π-conjugated ethynyl group. Although this architecture differs from that of classical amphiphiles and those of other ferrocene-based amphiphiles, the compound shows marked surfactant properties comparable to those of lipids, exhibiting a very low value of critical aggregation concentration in water (cac = 0.03 mM). It forms classical micelles only in a very narrow concentration range, which then convert into monolayer vesicles. Unlike classical surfactants, aggregates already form at a very low concentration, far beneath that required for the formation of a monolayer at the air-water interface. At even higher concentration, FcNMe3TIPS forms lyotropic liquid crystals, not only in contact with water, but also in a variety of organic solvents. As an additional intriguing feature, FcNMe3TIPS is amenable to a range of further modification reactions. The TIPS group is easily cleaved, and the resulting ethynyl function can be used to construct heterobimetallic platinum-ferrocene conjugates with trans-Pt(PEt3)2X (X = Cl, I) complex entities, leading to a heterobimetallic surfactant. We also found that the benzylic α-position of FcNMe3TIPS is rather reactive and that the attached ammonium group can be exchanged by other substituents (e.g., -CN), which offers additional opportunities for further functionalization. Although FcNMe3TIPS is reversibly oxidized in voltammetric and UV-vis spectroelectrochemical experiments, the high reactivity at the α-position is also responsible for the instability of the corresponding ferrocenium ion, leading to a polymerization reaction.
Collapse
|
134
|
Bertolazzo AA, Naullage PM, Peters B, Molinero V. The Clathrate-Water Interface Is Oleophilic. J Phys Chem Lett 2018; 9:3224-3231. [PMID: 29812945 DOI: 10.1021/acs.jpclett.8b01210] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
The slow nucleation of clathrate hydrates is a central challenge for their use in the storage and transportation of natural gas. Molecules that strongly adsorb to the clathrate-water interface decrease the crystal-water surface tension, lowering the barrier for clathrate nucleation. Surfactants are widely used to promote the nucleation and growth of clathrate hydrates. It has been proposed that these amphiphilic molecules bind to the clathrate surface via hydrogen bonding. However, recent studies reveal that PVCap, an amphiphilic polymer, binds to clathrates through hydrophobic moieties. Here we use molecular dynamic simulations and theory to investigate the mode and strength of binding of surfactants to the clathrate-water interface and their effect on the nucleation rate. We find that the surfactants bind to the clathrate-water interface exclusively through their hydrophobic tails. The binding is strong, driven by the entropy of dehydration of the alkyl chain, as it penetrates empty cavities at the hydrate surface. The hydrophobic attraction of alkyl groups to the clathrate surface also results in strong adsorption of alkanes. We identify two regimes for the binding of surfactants as a function of their density at the hydrate surface, which we interpret to correspond to the two steps of the Langmuir adsorption isotherm observed in experiments. Our results indicate that hydrophobic attraction to the clathrate-water interface is key for the design of soluble additives that promote the nucleation of hydrates. We use the calculated adsorption coefficients to estimate the concentration of sodium dodecyl sulfate (SDS) required to reach nucleation rates for methane hydrate consistent with those measured in experiments. To our knowledge, this study is the first to quantify the effect of surfactant concentration in the nucleation rate of clathrate hydrates.
Collapse
Affiliation(s)
- Andressa A Bertolazzo
- Department of Chemistry , The University of Utah , Salt Lake City , Utah 84112-0580 , United States
- Departamento de Ciências Exatas e Educação , Universidade Federal de Santa Catarina , Blumenau , State of Santa Catarina 88040-900 , Brazil
| | - Pavithra M Naullage
- Department of Chemistry , The University of Utah , Salt Lake City , Utah 84112-0580 , United States
| | - Baron Peters
- Department of Chemical Engineering , University of California , Santa Barbara , California 93106 , United States
| | - Valeria Molinero
- Department of Chemistry , The University of Utah , Salt Lake City , Utah 84112-0580 , United States
| |
Collapse
|
135
|
Meier AR, Yehl JB, Eckenroad KW, Manley GA, Strein TG, Rovnyak D. Stepwise Aggregation of Cholate and Deoxycholate Dictates the Formation and Loss of Surface-Available Chirally Selective Binding Sites. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2018; 34:6489-6501. [PMID: 29733655 DOI: 10.1021/acs.langmuir.8b00467] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Bile salts are facially amphiphilic, naturally occurring chemicals that aggregate to perform numerous biochemical processes. Because of their unique intermolecular properties, bile salts have also been employed as functional materials in medicine and separation science (e.g., drug delivery, chiral solubilization, purification of single-walled carbon nanotubes). Bile micelle formation is structurally complex, and it remains a topic of considerable study. Here, the exposed functionalities on the surface of cholate and deoxycholate micelles are shown to vary from one another and with the micelle aggregation state. Collectively, data from NMR and capillary electrophoresis reveal preliminary, primary, and secondary stepwise aggregation of the salts of cholic (CA) and deoxycholic (DC) acid in basic conditions (pH 12, 298 K), and address how the surface availability of chirally selective binding sites is dependent on these sequential stages of aggregation. Prior work has demonstrated sequential CA aggregation (pH 12, 298 K) including a preliminary CMC at ca. 7 mM (no chiral selection), followed by a primary CMC at ca. 14 mM that allows chiral selection of binaphthyl enantiomers. In this work, DC is also shown to form stepwise preliminary and primary aggregates (ca. 3 mM DC and 9 mM DC, respectively, pH 12, 298 K) but the preliminary 3 mM DC aggregate is capable of chirally selective solubilization of the binaphthyl enantiomers. Higher-order, secondary bile aggregates of each of CA and DC show significantly degraded chiral selectivity. Diffusion NMR reveals that secondary micelles of CA exclude the BNDHP guests, while secondary micelles of DC accommodate guests, but with a loss of chiral selectivity. These data lead to the hypothesis that secondary aggregates of DC have an exposed binding site, possibly the 7α-edge of a bile dimeric unit, while secondary CA micelles do not present binding edges to the solution, potentially instead exposing the three alcohol groups on the hydrophilic α-face to the solution.
Collapse
Affiliation(s)
- Adam R Meier
- Department of Chemistry , Bucknell University , 1 Dent Drive , Lewisburg , Pennsylvania 17837 , United States
| | - Jenna B Yehl
- Department of Chemistry , Bucknell University , 1 Dent Drive , Lewisburg , Pennsylvania 17837 , United States
| | - Kyle W Eckenroad
- Department of Chemistry , Bucknell University , 1 Dent Drive , Lewisburg , Pennsylvania 17837 , United States
| | - Gregory A Manley
- Department of Chemistry , Bucknell University , 1 Dent Drive , Lewisburg , Pennsylvania 17837 , United States
| | - Timothy G Strein
- Department of Chemistry , Bucknell University , 1 Dent Drive , Lewisburg , Pennsylvania 17837 , United States
| | - David Rovnyak
- Department of Chemistry , Bucknell University , 1 Dent Drive , Lewisburg , Pennsylvania 17837 , United States
| |
Collapse
|
136
|
Shao C, Tian H, Wang T, Wang Z, Chou S, Shan A, Cheng B. Central β-turn increases the cell selectivity of imperfectly amphipathic α-helical peptides. Acta Biomater 2018; 69:243-255. [PMID: 29355714 DOI: 10.1016/j.actbio.2018.01.009] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Revised: 01/09/2018] [Accepted: 01/09/2018] [Indexed: 12/19/2022]
Abstract
Although membrane lytic antimicrobial peptides (AMPs) show enormous potential for addressing mounting global antibiotic resistance, therapeutic applications are hindered by their weak antimicrobial activity, high toxicity, salt sensitivity and poor understanding of structure-activity relationships. To investigate the effects of different parameters on the biological activities of AMPs, a rational approach was adopted to design a series of short cationic α-helical peptides comprising the Ac-WxKyWxzzyKxWyK-NH2 sequence, where x: cationic residues (Arg or Lys), y: hydrophobic residues (Ala, Val, Ile or Leu), and zz: β-turn (rigid D-Pro-Gly turn or flexible Gly-Gly turn). The peptides showed a more helical structure as the concentration of membrane-mimetic solution increased. The peptide RL with a central D-Pro-Gly turn (x: Arg, y: Lys, zz = D-Pro-Gly) exhibited broad-spectrum antimicrobial activities (2-8 μM) against ten types of clinically relevant microorganisms and even maintained its activity in the presence of physiological salts and showed excellent selectivity toward bacterial cells over human red blood cells and mammalian cells. However, the toxicity was increased after the removal of D-Pro-Gly turn. Additionally, the bactericidal activity was reduced when the D-Pro-Gly turn was replaced by a Gly-Gly turn. Fluorescence spectroscopy and electron microscopy analyses indicated that RL and its derivatives killed microbial cells by permeabilizing the cell membrane and damaging membrane integrity. In conclusion, these findings clearly generalized a potential method for designing or optimizing AMPs, and the peptide RL is a promising therapeutic candidate to combat antibiotic resistance. STATEMENT OF SIGNIFICANCE We proposed a rational approach to design imperfectly amphiphilic peptides and identified RL (Ac-WRKLWRpGLKRWLK-NH2) in particular that shows strong antibacterial properties, low toxicity and high salt resistance. The β-turn unit inserted into the central position of cationic α-helical peptides, especially the D-Pro-Gly turn, significantly increase the cell selectivity of the synthetic amphiphiles. The findings demonstrate a potential method for designing and/or optimizing AMPs, which would facilitate the development of strategies to design peptide-based antimicrobial biomaterials in a variety of biotechnological and clinical applications.
Collapse
|
137
|
Wang Y, Yan F, Jia Q, Wang Q. Quantitative structure-property relationship for critical micelles concentration of sugar-based surfactants using norm indexes. J Mol Liq 2018. [DOI: 10.1016/j.molliq.2018.01.037] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
138
|
Sinn S, Yang L, Biedermann F, Wang D, Kübel C, Cornelissen JJLM, De Cola L. Templated Formation of Luminescent Virus-like Particles by Tailor-Made Pt(II) Amphiphiles. J Am Chem Soc 2018; 140:2355-2362. [PMID: 29357236 PMCID: PMC5817621 DOI: 10.1021/jacs.7b12447] [Citation(s) in RCA: 37] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
![]()
Virus-like particles
(VLPs) have been created from luminescent
Pt(II) complex amphiphiles, able to form supramolecular structures
in water solutions, that can be encapsulated or act as templates of
cowpea chlorotic mottle virus capsid proteins. By virtue of a bottom-up
molecular design, icosahedral and nonicosahedral (rod-like) VLPs have
been constructed through diverse pathways, and a relationship between
the molecular structure of the complexes and the shape and size of
the VLPs has been observed. A deep insight into the mechanism for
the templated formation of the differently shaped VLPs was achieved,
by electron microscopy measurements (TEM and STEM) and bulk analysis
(FPLC, DLS, photophysical investigations). Interestingly, the obtained
VLPs can be visualized by their intense emission at room temperature,
generated by the self-assembly of the Pt(II) complexes. The encapsulation
of the luminescent species is further verified by their higher emission
quantum yields inside the VLPs, which is due to the confinement effect
of the protein cage. These hybrid materials demonstrate the potential
of tailor-made supramolecular systems able to control the assembly
of biological building blocks.
Collapse
Affiliation(s)
- Stephan Sinn
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg & CNRS , 8 Rue Gaspard Monge, 67000 Strasbourg, France
| | - Liulin Yang
- Laboratory for Biomolecular Nanotechnology, MESA+ Institute, University of Twente , P.O. Box 207, 7500 AE Enschede, The Netherlands
| | | | | | | | - Jeroen J L M Cornelissen
- Laboratory for Biomolecular Nanotechnology, MESA+ Institute, University of Twente , P.O. Box 207, 7500 AE Enschede, The Netherlands
| | - Luisa De Cola
- Institut de Science et d'Ingénierie Supramoléculaires (ISIS), Université de Strasbourg & CNRS , 8 Rue Gaspard Monge, 67000 Strasbourg, France
| |
Collapse
|
139
|
Interactions of hyaluronan with oppositely charged surfactants in very diluted solutions in water. Int J Biol Macromol 2018; 112:241-249. [PMID: 29391230 DOI: 10.1016/j.ijbiomac.2018.01.176] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2017] [Revised: 01/11/2018] [Accepted: 01/26/2018] [Indexed: 11/23/2022]
Abstract
The phase behavior of aqueous systems containing hyaluronan, at concentrations between 2 and 100 mg/L, and oppositely charged surfactants was investigated. A fluorescence probe technique revealed the formation of micellar structures on the hyaluronan in homogeneous systems well below the surfactant standard, critical, micellar concentration. Moreover, regions of gel-phase separation were revealed. A detailed phase diagram was, thus, constructed in the very diluted region and the hyaluronan concentration was found to be the main parameter controlling the phase behavior, in contrast to the charge ratio. The stability of hyaluronan-surfactant aggregates in the homogeneous systems while in storage at 4 °C (up to three months), against dilution, salt addition and on heating-cooling (between 10 and 50 °C) was also investigated. The aggregates were stable while in storage or upon increasing and decreasing the temperature. The dilution of hyaluronan-surfactant complexes or the addition of 0.15 M NaCl led to their disintegration. Finally, systems prepared in a 0.15 M NaCl solution showed that interactions are suppressed and no aggregation below the standard critical micellar concentration was observed.
Collapse
|
140
|
Prajapati R, Mukherjee TK. Effect of surfactant assemblies on the resonance energy transfer from 4′,6-diamidino-2-phenylindole to silver nanoclusters. J Photochem Photobiol A Chem 2018. [DOI: 10.1016/j.jphotochem.2017.11.016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
|
141
|
Hussain E, Hu Z, Zhou H, He C, Shahzad SA, Yu C. Benzo[ghi]perylene and coronene: ratiometric fluorescent probes for the sensing of microenvironment changes and micelle formation in aqueous medium. NEW J CHEM 2018. [DOI: 10.1039/c8nj00739j] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Benzo[ghi]perylene and coronene were used as ratiometric fluorescent probes to monitor microenvironment changes and monomer–micelle transition for the first time.
Collapse
Affiliation(s)
- Ejaz Hussain
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Zhenzhen Hu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Huipeng Zhou
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Chunhua He
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Sohail Anjum Shahzad
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Cong Yu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| |
Collapse
|
142
|
Huang Z, Parikh S, Fish WP. Interactions between a poorly soluble cationic drug and sodium dodecyl sulfate in dissolution medium and their impact on in vitro dissolution behavior. Int J Pharm 2018; 535:350-359. [DOI: 10.1016/j.ijpharm.2017.10.063] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2017] [Revised: 10/18/2017] [Accepted: 10/31/2017] [Indexed: 11/29/2022]
|
143
|
Galipeau K, Socki M, Socia A, Harmon PA. Incomplete Loading of Sodium Lauryl Sulfate and Fasted State Simulated Intestinal Fluid Micelles Within the Diffusion Layers of Dispersed Drug Particles During Dissolution. J Pharm Sci 2018. [DOI: 10.1016/j.xphs.2017.06.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
144
|
Hussain E, Niu N, Zhou H, Shahzad SA, Yu C. Aggregation enhanced excimer emission (AEEE) of benzo[ghi]perylene and coronene: multimode probes for facile monitoring and direct visualization of micelle transition. Analyst 2018; 143:4283-4289. [DOI: 10.1039/c8an01070f] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Excimer to monomer transition of multimode probes facilitating the accurate monitoring and direct visualization of monomer–micelle transition.
Collapse
Affiliation(s)
- Ejaz Hussain
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Niu Niu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Huipeng Zhou
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Sohail Anjum Shahzad
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| | - Cong Yu
- State Key Laboratory of Electroanalytical Chemistry
- Changchun Institute of Applied Chemistry
- Chinese Academy of Sciences
- Changchun
- P. R. China
| |
Collapse
|
145
|
Tubaon RM, Haddad PR, Quirino JP. Electrokinetic Removal of Dodecyl Sulfate Micelles from Digested Protein Samples Prior to Electrospray-Ionization Mass Spectrometry. Anal Chem 2017; 89:13058-13063. [DOI: 10.1021/acs.analchem.7b03009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Ria Marni Tubaon
- Australian Centre for Research
on Separation Science, School of Physical Sciences- Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Paul R. Haddad
- Australian Centre for Research
on Separation Science, School of Physical Sciences- Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| | - Joselito P. Quirino
- Australian Centre for Research
on Separation Science, School of Physical Sciences- Chemistry, University of Tasmania, Hobart, Tasmania 7001, Australia
| |
Collapse
|
146
|
Saitoh T, Shibata K, Fujimori K, Ohtani Y. Rapid removal of tetracycline antibiotics from water by coagulation-flotation of sodium dodecyl sulfate and poly(allylamine hydrochloride) in the presence of Al(III) ions. Sep Purif Technol 2017. [DOI: 10.1016/j.seppur.2017.06.036] [Citation(s) in RCA: 63] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/07/2022]
|
147
|
Delpuech JJ, Dupont-Leclercq L, Parant S, Henry B. NMR Evidence for Grotthuss-like Proton Diffusion on the Surface of N-Alkyl-ammonium Micelles in Acidic Aqueous Solution. J SOLUTION CHEM 2017. [DOI: 10.1007/s10953-017-0672-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
148
|
Chaotropes trigger conformational rearrangements differently in Concanavalin A. J CHEM SCI 2017. [DOI: 10.1007/s12039-017-1333-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
|
149
|
Kos P, Pavli M, Baumgartner S, Kogej K. Release mechanism of doxazosin from carrageenan matrix tablets: Effect of ionic strength and addition of sodium dodecyl sulphate. Int J Pharm 2017. [PMID: 28648579 DOI: 10.1016/j.ijpharm.2017.06.067] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
The polyelectrolyte matrix tablets loaded with an oppositely charged drug exhibit complex drug-release mechanisms. In this study, the release mechanism of a cationic drug doxazosin mesylate (DM) from matrix tablets based on an anionic polyelectrolyte λ-carrageenan (λ-CARR) is investigated. The drug release rates from λ-CARR matrices are correlated with binding results based on potentiometric measurements using the DM ion-sensitive membrane electrode and with molecular characteristics of the DM-λ-CARR-complex particles through hydrodynamic size measurements. Experiments are performed in solutions with different ionic strength and with the addition of an anionic surfactant sodium dodecyl sulphate (SDS). It is demonstrated that in addition to swelling and erosion of tablets, the release rates depend strongly on cooperative interactions between DM and λ-CARR. Addition of SDS at concentrations below its critical micelle concentration (CMC) slows down the DM release through hydrophobic binding of SDS to the DM-λ-CARR complex. On the contrary, at concentrations above the CMC SDS pulls DM from the complex by forming mixed micelles with it and thus accelerates the release. Results involving SDS show that the concentration of surfactants that are naturally present in gastrointestinal environment may have a great impact on the drug release process.
Collapse
Affiliation(s)
- Petra Kos
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI-1000 Ljubljana, Slovenia
| | - Matej Pavli
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI-1000 Ljubljana, Slovenia; Krka d.d., Novo mesto, Šmarješka cesta 6, SI-8501 Novo mesto, Slovenia
| | - Saša Baumgartner
- Faculty of Pharmacy, University of Ljubljana, Aškerčeva 7, SI-1000 Ljubljana, Slovenia
| | - Ksenija Kogej
- Department of Chemistry and Biochemistry, Faculty of Chemistry and Chemical Technology, University of Ljubljana, Večna pot 113, SI-1000 Ljubljana, Slovenia.
| |
Collapse
|
150
|
Atkinson J, Clarke MW, Warnica JM, Boddington KF, Graether SP. Structure of an Intrinsically Disordered Stress Protein Alone and Bound to a Membrane Surface. Biophys J 2017; 111:480-491. [PMID: 27508433 DOI: 10.1016/j.bpj.2016.07.001] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Revised: 06/25/2016] [Accepted: 07/01/2016] [Indexed: 12/19/2022] Open
Abstract
Dehydrins are a group of intrinsically disordered proteins that protect plants from damage caused by drought, cold, and high salinity. Like other intrinsically disordered proteins, dehydrins can gain structure when bound to a ligand. Previous studies have shown that dehydrins are able to protect liposomes from cold damage, but the interactions that drive membrane binding and the detailed structure of the bound and unbound forms are not known. We use an ensemble-structure approach to generate models of a dehydrin known as K2 in the presence and absence of sodium dodecyl sulfate micelles, and we docked the bound structure to the micelle. The collection of residual dipolar coupling data, amide protection factors, and paramagnetic relaxation enhancement distances, in combination with chemical shifts and relaxation measurements, allows for determining plausible structures that are not otherwise visible in time-averaged structural data. The results show that in the bound structure, the conserved lysines are important for membrane binding, whereas the flanking hydrophobic residues play a lesser role. The unbound structure shows a high level of disorder and an extended structure. We propose that the structural differences between bound and unbound forms allow dehydrins to act as molecular shields in their unbound state and as membrane protectants in their bound state. Unlike α-synuclein, the significant gain of α-helicity in K2 at low concentrations of sodium dodecyl sulfate is not due to a decrease in the critical micelle concentration. The study provides structural insight into how a disordered protein can interact with a membrane surface.
Collapse
Affiliation(s)
- John Atkinson
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Matthew W Clarke
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Josephine M Warnica
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Kelly F Boddington
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada
| | - Steffen P Graether
- Department of Molecular and Cellular Biology, University of Guelph, Guelph, Ontario, Canada.
| |
Collapse
|