1
|
Bielec K, Kowalski A, Bubak G, Witkowska Nery E, Hołyst R. Ion Complexation Explains Orders of Magnitude Changes in the Equilibrium Constant of Biochemical Reactions in Buffers Crowded by Nonionic Compounds. J Phys Chem Lett 2022; 13:112-117. [PMID: 34962392 PMCID: PMC8762655 DOI: 10.1021/acs.jpclett.1c03596] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 12/22/2021] [Indexed: 06/14/2023]
Abstract
The equilibrium constant (K) of biochemical complex formation in aqueous buffers with high concentration (>20 wt %) of nonionic compounds can vary by orders of magnitude in comparison with the K in a pure buffer. The precise molecular mechanisms of these profound changes are not known. Herein, we show up to a 1000-fold decrease of the K value of DNA hybridization (at nM concentration) in standard molecular crowder systems such as PEG, dextrans, Ficoll, and glycerol. The effect responsible for the decrease of K is the complexation of positively charged ions from a buffer by nonionic polymers/small molecules. We determined the average equilibrium constant for the complexation of ions per monomer (∼0.49 M-1). We retrieve K's original value for a pure buffer if we properly increase the ionic strength of the buffer crowded by the polymers, compensating for the loss of complexed ions.
Collapse
Affiliation(s)
- Krzysztof Bielec
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 01-224 Warsaw, Poland
- Institute
of Chemical Sciences and Engineering,
EPFL CH C2 425, Bâtiment CH, Station 6, Lausanne CH-1015, Switzerland
| | - Adam Kowalski
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 01-224 Warsaw, Poland
| | - Grzegorz Bubak
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 01-224 Warsaw, Poland
| | | | - Robert Hołyst
- Institute
of Physical Chemistry, Polish Academy of
Sciences, 01-224 Warsaw, Poland
| |
Collapse
|
2
|
Karpińska A, Pilz M, Buczkowska J, Żuk PJ, Kucharska K, Magiera G, Kwapiszewska K, Hołyst R. Quantitative analysis of biochemical processes in living cells at a single-molecule level: a case of olaparib-PARP1 (DNA repair protein) interactions. Analyst 2021; 146:7131-7143. [PMID: 34726203 DOI: 10.1039/d1an01769a] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Quantitative description of biochemical processes inside living cells and at single-molecule levels remains a challenge at the forefront of modern instrumentation and spectroscopy. This paper demonstrates such single-cell, single-molecule analyses performed to study the mechanism of action of olaparib - an up-to-date, FDA-approved drug for germline-BRCA mutated metastatic breast cancer. We characterized complexes formed with PARPi-FL - fluorescent analog of olaparib in vitro and in cancer cells using the advanced fluorescent-based method: Fluorescence Correlation Spectroscopy (FCS) combined with a length-scale dependent cytoplasmic/nucleoplasmic viscosity model. We determined in vitro olaparib-PARP1 equilibrium constant (6.06 × 108 mol L-1). In the cell nucleus, we distinguished three states of olaparib: freely diffusing drug (24%), olaparib-PARP1 complex (50%), and olaparib-PARP1-RNA complex (26%). We show olaparib accumulation in 3D spheroids, where intracellular concentration is twofold higher than in 2D cells. Moreover, olaparib concentration was tenfold higher (506 nmol L-1vs. 57 nmol L-1) in cervical cancer (BRCA1 high abundance) than in breast cancer cells (BRCA1 low abundance) but with a lower toxic effect. Thus we confirmed that the amount of BRCA1 protein in the cells is a better predictor of the therapeutic effect of olaparib than its penetration into cancer tissue. Our single-molecule and single-cell approach give a new perspective of drug action in living cells. FCS provides a detailed in vivo insight, valuable in drug development and targeting.
Collapse
Affiliation(s)
- Aneta Karpińska
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Marta Pilz
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Joanna Buczkowska
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Paweł J Żuk
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland. .,Department of Physics, Lancaster University, Lancaster LA1 4YB, UK
| | - Karolina Kucharska
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Gaweł Magiera
- Department of Medicine, Poznan University of Medical Sciences, 60-356, Poznan, Poland
| | - Karina Kwapiszewska
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| | - Robert Hołyst
- Institute of Physical Chemistry Polish Academy of Sciences, Kasprzaka 44/52, 01-224, Warsaw, Poland.
| |
Collapse
|
3
|
Khamari L, Pramanik S, Shekhar S, Mahato P, Mukherjee S. Preferential Binding of Epirubicin Hydrochloride with Single Nucleotide Mismatched DNA and Subsequent Sequestration by a Mixed Micelle. J Phys Chem B 2021; 125:11660-11672. [PMID: 34652157 DOI: 10.1021/acs.jpcb.1c06944] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Targeting mismatched base pairs containing DNA using small molecules and exploring the underlying mechanism involved during the binding interactions is one of the fundamental aspects of drug design. These molecules in turn are used in nucleic acid targeted therapeutics and cancer diagnosis. In this work, we systematically delineate the binding of the anticancer drug, epirubicin hydrochloride (EPR) with 20-mer duplex DNA, having both natural nucleobase pairing and thermodynamically least stable non-Watson-Crick base pairing. From the thermal denaturation studies, we observed that EPR can remarkably enhance the thermal stability of cytosine-cytosine (CC) and cytosine-thymine (CT) mismatched (MM) DNA over other 20-mer duplex DNA. From steady-state fluorescence spectroscopy and isothermal titration calorimetry studies, we concluded that EPR binds strongly with the mismatched duplex DNA through the intercalation binding mode. The interaction of EPR and duplex DNA has also been monitored at a single molecular resolution using fluorescence correlation spectroscopy (FCS). Dynamic quantitates such as diffusion coefficients and hydrodynamic radii obtained from an FCS study along with association and dissociation rate constants estimated from intensity time trace analyses further substantiate the stronger binding affinity of EPR to the thermally less stable mismatched DNA, formed by the most discriminating nucleobase (viz. cytosine). Additionally, we have shown that EPR can be sequestered from nucleic acids using a mixed micellar system of an anionic surfactant and a triblock copolymer. From thermal denaturation studies and circular dichroism spectroscopy, we found that the extent of drug sequestration depends on the binding affinity of EPR to the duplex DNA, and this mixed micellar system can be employed for the removal of excess drug in the case of a drug overdose.
Collapse
Affiliation(s)
- Laxmikanta Khamari
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Srikrishna Pramanik
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Shashi Shekhar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Paritosh Mahato
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| | - Saptarshi Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 462066, Madhya Pradesh, India
| |
Collapse
|
4
|
Kucharska K, Pilz M, Bielec K, Kalwarczyk T, Kuźma P, Hołyst R. Two Intercalation Mechanisms of Oxazole Yellow Dimer (YOYO-1) into DNA. Molecules 2021; 26:molecules26123748. [PMID: 34205435 PMCID: PMC8234192 DOI: 10.3390/molecules26123748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2021] [Revised: 06/14/2021] [Accepted: 06/15/2021] [Indexed: 11/16/2022] Open
Abstract
The oxazole yellow dye, YOYO-1 (a symmetric homodimer), is a commonly used molecule for staining DNA. We applied the brightness analysis to study the intercalation of YOYO-1 into the DNA. We distinguished two binding modes of the dye to dsDNA: mono-intercalation and bis-intercalation. Bis-intercalation consists of two consecutive mono-intercalation steps, characterised by two distinct equilibrium constants (with the average number of base pair per binding site equals 3.5): K1=3.36±0.43×107M−1 and K2=1.90±0.61×105M−1, respectively. Mono-intercalation dominates at high concentrations of YOYO-1. Bis-intercalation occurs at low concentrations.
Collapse
|
5
|
Khamari L, Pramanik U, Shekhar S, Mohanakumar S, Mukherjee S. Thermal Reversibility and Structural Stability in Lysozyme Induced by Epirubicin Hydrochloride. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2021; 37:3456-3466. [PMID: 33703900 DOI: 10.1021/acs.langmuir.1c00179] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Herein we report the binding interactions between lysozyme (Lyz) and an anthracycline drug, epirubicin hydrochloride (EPR), through an extensive spectroscopic approach at both ensemble average and single molecular resolution. Our steady-state and time-resolved fluorescence spectroscopy reveals that the drug-induced fluorescence quenching of the protein proceeds through a static quenching mechanism. Isothermal titration calorimetry (ITC) and steady-state experiments reveal almost similar thermodynamic signatures of the drug-protein interactions. The underlying force that plays pivotal roles in the said interaction is hydrophobic in nature, which is enhanced in the presence of a strong electrolyte (NaCl). Circular dichroism (CD) spectra indicate that there is a marginal increase in the secondary structure of the native protein (α-helical content increases from 26.9 to 31.4% in the presence of 100 μM EPR) upon binding with the drug. Fluorescence correlation spectroscopy (FCS) was used to monitor the changes in structure and conformational dynamics of Lyz upon interaction with EPR. The individual association (Kass = 0.33 × 106 ms-1 M-1) and dissociation (Kdiss = 1.79 ms-1) rate constants and the binding constant (Kb = 1.84 × 105 M-1) values, obtained from fluctuations of fluorescence intensity of the EPR-bound protein, have also been estimated. AutoDock results demonstrate that the drug molecule is encapsulated within the hydrophobic pocket of the protein (in close proximity to both Trp62 and Trp108) and resides ∼20 Å apart from the covalently labelled CPM dye. Förster resonance energy transfer (FRET) studies proved that the distance between the donor (CPM) and the acceptor (EPR) is ∼22 Å, which is very similar to that obtained from molecular docking analysis (∼20 Å). The system also shows temperature-dependent reversible FRET, which may be used as a thermal sensor for the temperature-sensitive biological systems.
Collapse
Affiliation(s)
- Laxmikanta Khamari
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 426 066, Madhya Pradesh, India
| | - Ushasi Pramanik
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 426 066, Madhya Pradesh, India
| | - Shashi Shekhar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 426 066, Madhya Pradesh, India
| | - Shilpa Mohanakumar
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 426 066, Madhya Pradesh, India
| | - Saptarshi Mukherjee
- Department of Chemistry, Indian Institute of Science Education and Research Bhopal, Bhopal Bypass Road, Bhauri, Bhopal 426 066, Madhya Pradesh, India
| |
Collapse
|