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Wang Z, Si J, Song Z, Zhang P, Wang J, Hao Y, Li W, Zhang P, Miao S. Precise and instrumental measurement of thermodynamics and kinetics of froth flotation by langmuir-blodgett technique. Colloids Surf A Physicochem Eng Asp 2020. [DOI: 10.1016/j.colsurfa.2020.125337] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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Amin NU, Siddiqi HM, Kun Lin Y, Hussain Z, Majeed N. Bovine Serum Albumin Protein-Based Liquid Crystal Biosensors for Optical Detection of Toxic Heavy Metals in Water. SENSORS (BASEL, SWITZERLAND) 2020; 20:E298. [PMID: 31948064 PMCID: PMC6982898 DOI: 10.3390/s20010298] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/13/2019] [Revised: 12/17/2019] [Accepted: 12/31/2019] [Indexed: 01/05/2023]
Abstract
A new methodology involving the use of Bovine Serum Albumin (BSA) as a probe and liquid crystal (LC) as a signal reporter for the detection of heavy metal ions in water at neutral pH was developed. BSA acted as a multi-dentate ligand for the detection of multiple metal ions. The LC sensor was fabricated by immobilizing 3 µg mL-1 BSA solution on dimethyloctadecyl-[3-(trimethoxysilyl)propyl]ammonium chloride (DMOAP)-coated glass slides. In the absence of heavy metal ions, a dark optical image was observed, while in their presence, a dark optical image turned to bright. The optical response was characterized by using a polarized optical microscope (POM). The BSA based LC sensor selectively detected toxic metal ions as compared to s block metal ions and ammonium ions in water. Moreover, the limit of detection was found to be very low (i.e., 1 nM) for the developed new biosensor in comparison to reported biosensors.
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Affiliation(s)
- Noor ul Amin
- Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan; (N.u.A.); (N.M.)
- Department of Chemical & Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Humaira Masood Siddiqi
- Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan; (N.u.A.); (N.M.)
| | - Yang Kun Lin
- Department of Chemical & Biomolecular Engineering, National University of Singapore, 4 Engineering Drive 4, Singapore 117585, Singapore
| | - Zakir Hussain
- School of Chemical and Materials Engineering (SCME), National University of Sciences and Technology (NUST), H-12, Islamabad 44000, Pakistan;
| | - Nasir Majeed
- Department of Chemistry, Quaid-i-Azam University, Islamabad 45320, Pakistan; (N.u.A.); (N.M.)
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Srivastav AK, Gupta SK, Kumar U. A molecular simulation approach towards the development of universal nanocarriers by studying the pH- and electrostatic-driven changes in the dynamic structure of albumin. RSC Adv 2020; 10:13451-13459. [PMID: 35492989 PMCID: PMC9051469 DOI: 10.1039/d0ra00803f] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2020] [Accepted: 03/14/2020] [Indexed: 01/15/2023] Open
Abstract
To explore the intramolecular interactions of protein, and its folding and unfolding mechanisms, we performed a simulation-based comparative study on albumin at different ionic strengths and pH. In this study, we performed molecular dynamics (MD) simulation for bovine serum albumin (BSA) at five different concentrations of NaCl (10, 20, 30, 40 and 50 mM), and five different pH values (2.0, 3.5, 4.3, 7.4, and 9.0). Herein, our aim was to unravel the effects of both pH and ionic strength on the conformations of the serum albumin structure. Our results indicate the effects of physicochemical factors in promoting conformational changes in the albumin structure, unlocking the hydrophobic sequences for hydrophobic drug binding. The BSA structure showed similarity to its native state in the pH range of 4.5 to 7.4 and at various ionic concentrations of NaCl. In the pH range of 3.5 to 4.5, the BSA structure showed denaturation in a controlled manner, which caused significant conformational changes in the molecular position of its hydrophobic amino acid residues. The resultant 3D structure gives insight into the amino acid trajectories. High denaturation and unstable behavior in the structural and conformational changes of the protein structure were observed at pH 2.0 and pH 9.0. We believe that these results and conditions will be helpful in the development of protein-based universal nanocarriers for the encapsulation of both hydrophilic and hydrophobic drugs. Role of pH and electrostatic charges on the conformations and dynamics of albumin structure by molecular dynamic study.![]()
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Affiliation(s)
| | - Sanjeev K. Gupta
- Computational Materials and Nanoscience Group
- Department of Physics
- St. Xavier's College
- Ahmedabad 380009
- India
| | - Umesh Kumar
- School of Nano Sciences
- Central University of Gujarat
- Gandhinagar
- India
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Putra RP, Ikumura Y, Horino H, Hori A, Rzeznicka II. Adsorption and Conformation of Bovine Serum Albumin with Blue-Emitting Gold Nanoclusters at the Air/Water and Lipid/Water Interfaces. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:16576-16582. [PMID: 31763843 DOI: 10.1021/acs.langmuir.9b02831] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Protein-encapsulated nanoclusters (NCs) are emerging as a versatile platform for in-vivo imaging and other biomedical applications due to their ultrasmall size and excitation in the near-infrared region. Encapsulation may however affect protein structure, size, charge, and its interaction with lipid membranes. In this study, bulk characterization methods along with surface-sensitive vibrational sum-frequency generation (VSFG) spectroscopy were employed to study the secondary structure of bovine serum albumin (BSA) with blue-emitting Au8NCs at the air/water and 1,2-dipalmitoyl-sn-glycero-3-phospho-(1'-rac-glycerol) (DPPG) lipid/water interfaces. With this approach, the difference in the adsorption behavior between native BSA and BSA with an increasing number of blue-emitting NCs was investigated under different pH conditions. At pH 7, at which both BSA and the lipid are negatively charged, protein molecules are found to associate with the DPPG monolayer via hydrophobic interactions with no preferential orientation across the lipid monolayer. At pH 3, adsorption of BSA at the DPPG monolayer occurs mainly due to electrostatic interactions between the negatively charged lipid headgroups and the positively charged protein, resulting in a uniform orientation of the protein across the lipid monolayer. Complimentary bulk studies by circular dichroism and particle size measurements show that the encapsulation of Au8NCs is associated with the loss of BSA helicity, which makes BSA-encapsulated Au8NCs prone to oligomerization, especially at a high content of Au8NCs at one BSA protein. The results indicate that the hydrodynamic diameter of BSA with Au8NCs strongly depends on the molar fraction of gold, the pH, and the storage time. A prolonged storage of Au8NCs@BSA at pH 7 increases the rate of protein oligomerization.
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Affiliation(s)
- Ridwan P Putra
- Graduate School of Engineering and Science , Shibaura Institute of Technology , Fukasaku 307 , 337-8570 Saitama , Japan
| | - Yoshinori Ikumura
- Graduate School of Engineering and Science , Shibaura Institute of Technology , Fukasaku 307 , 337-8570 Saitama , Japan
| | - Hideyuki Horino
- Department of Chemistry for Materials, Graduate School of Engineering , Mie University , 1577 Kurimamachiya-cho , 514-8507 Tsu , Mie , Japan
| | - Akiko Hori
- Graduate School of Engineering and Science , Shibaura Institute of Technology , Fukasaku 307 , 337-8570 Saitama , Japan
| | - Izabela I Rzeznicka
- Graduate School of Engineering and Science , Shibaura Institute of Technology , Fukasaku 307 , 337-8570 Saitama , Japan
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Li Y, Shrestha M, Luo M, Sit I, Song M, Grassian VH, Xiong W. Salting Up of Proteins at the Air/Water Interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2019; 35:13815-13820. [PMID: 31584824 DOI: 10.1021/acs.langmuir.9b01901] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Vibrational sum frequency generation (VSFG) spectroscopy and surface pressure measurements are used to investigate the adsorption of a globular protein, bovine serum albumin (BSA), at the air/water interface with and without the presence of salts. We find at low (2 to 5 ppm) protein concentrations, which is relevant to environmental conditions, both VSFG and surface pressure measurements of BSA behave drastically different from at higher concentrations. Instead of emerging to the surface immediately, as observed at 1000 ppm, protein adsorption kinetics is on the order of tens of minutes at lower concentrations. Most importantly, salts strongly enhance the presence of BSA at the interface. This "salting up" effect differs from the well-known "salting out" effect as it occurs at protein concentrations well-below where "salting out" occurs. The dependence on salt concentration suggests this effect relates to a large extent electrostatic interactions and volume exclusion. Additionally, results from other proteins and the pH dependence of the kinetics indicate that salting up depends on the flexibility of proteins. This initial report demonstrates "salting up" as a new type of salt-driven interfacial phenomenon, which is worthy of continued investigation given the importance of salts in biological and environmental aqueous systems.
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Suquila FAC, Tarley CRT. Performance of restricted access copper-imprinted poly(allylthiourea) in an on-line preconcentration and sample clean-up FIA-FAAS system for copper determination in milk samples. Talanta 2019; 202:460-468. [DOI: 10.1016/j.talanta.2019.05.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2019] [Revised: 05/01/2019] [Accepted: 05/03/2019] [Indexed: 01/31/2023]
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Rotational diffusion of magnetic nanoparticles in protein solutions. J Colloid Interface Sci 2017; 506:393-402. [DOI: 10.1016/j.jcis.2017.07.009] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 06/30/2017] [Accepted: 07/02/2017] [Indexed: 12/19/2022]
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Brosel-Oliu S, Galyamin D, Abramova N, Muñoz-Pascual FX, Bratov A. Impedimetric label-free sensor for specific bacteria endotoxin detection by surface charge registration. Electrochim Acta 2017. [DOI: 10.1016/j.electacta.2017.05.060] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
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Polypeptide-Nanoparticle Interactions and Corona Formation Investigated by Monte Carlo Simulations. Polymers (Basel) 2016; 8:polym8060203. [PMID: 30979300 PMCID: PMC6432162 DOI: 10.3390/polym8060203] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2016] [Revised: 05/11/2016] [Accepted: 05/12/2016] [Indexed: 12/23/2022] Open
Abstract
Biomacromolecule activity is usually related to its ability to keep a specific structure. However, in solution, many parameters (pH, ionic strength) and external compounds (polyelectrolytes, nanoparticles) can modify biomacromolecule structure as well as acid/base properties, thus resulting in a loss of activity and denaturation. In this paper, the impact of neutral and charged nanoparticles (NPs) is investigated by Monte Carlo simulations on polypeptide (PP) chains with primary structure based on bovine serum albumin. The influence of pH, salt valency, and NP surface charge density is systematically studied. It is found that the PP is extended at extreme pH, when no complex formation is observed, and folded at physiological pH. PP adsorption around oppositely-charged NPs strongly limits chain structural changes and modifies its acid/base properties. At physiological pH, the complex formation occurs only with positively-charged NPs. The presence of salts, in particular those with trivalent cations, introduces additional electrostatic interactions, resulting in a mitigation of the impact of negative NPs. Thus, the corona structure is less dense with locally-desorbed segments. On the contrary, very limited impact of salt cation valency is observed when NPs are positive, due to the absence of competitive effects between multivalent cations and NP.
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Lavoisier A, Schlaeppi JM. Early developability screen of therapeutic antibody candidates using Taylor dispersion analysis and UV area imaging detection. MAbs 2015; 7:77-83. [PMID: 25514497 PMCID: PMC4623059 DOI: 10.4161/19420862.2014.985544] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Therapeutic antibodies represent one of the fastest growing segments in the pharmaceutical market. They are used in a broad range of disease fields, such as autoimmune diseases, cancer, inflammation and infectious diseases. The growth of the segment has necessitated development of new analytical platforms for faster and better antibody selection and characterization. Early quality control and risk assessment of biophysical parameters help prevent failure in later stages of antibody development, and thus can reduce costs and save time. Critical parameters such as aggregation, conformational stability, colloidal stability and hydrophilicity, are measured during the early phase of antibody generation and guide the selection process of the best lead candidates in terms of technical developability. We report on the use of a novel instrument (ActiPix/Viscosizer) for measuring both the hydrodynamic radius and the absolute viscosity of antibodies based on Taylor dispersion analysis and UV area imaging. The looped microcapillary-based method combines low sample consumption, fast throughput and high precision compared to other conventional methods. From a random panel of 130 antibodies in the early selection process, we identified some with large hydrodynamic radius outside the normal distribution and others with non-Gaussian Taylor dispersion profiles. The antibodies with such abnormal properties were confirmed later in the selection process to show poor developability profiles. Moreover, combining these results with those of the viscosity measurements at high antibody concentrations allows screening, with limited amounts of materials, candidates with potential issues in pre-formulation development.
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Affiliation(s)
- Alexandra Lavoisier
- a Biologics Center ; Novartis Institutes for Biomedical Research ; Basel , Switzerland
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Riccardi K, Cawley S, Yates PD, Chang C, Funk C, Niosi M, Lin J, Di L. Plasma Protein Binding of Challenging Compounds. J Pharm Sci 2015; 104:2627-36. [DOI: 10.1002/jps.24506] [Citation(s) in RCA: 59] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2015] [Revised: 04/25/2015] [Accepted: 04/27/2015] [Indexed: 01/10/2023]
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