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Jaganathan M, Dhathathreyan A. Conformational transitions of cytochrome c in sub-micron-sized capsules at air/buffer interface. LANGMUIR : THE ACS JOURNAL OF SURFACES AND COLLOIDS 2014; 30:11356-11365. [PMID: 25233344 DOI: 10.1021/la5024696] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
This work presents the design of sub-micron-sized capsules of Cytochrome c (cyt c) in the range 300-350 nm and the conformational transitions of the protein that occur when the films of these capsules spread at the air/buffer interface are subjected to repeated compression-expansion cycles. Steady state fluorescence, time-resolved fluorescence, and circular dichroic (CD) spectra have been used to study the highly compact native conformation (70% helicity) of the protein in the capsules and its stability has been analyzed using cyclic voltammetry. The capsules have been characterized using zeta sizer and high resolution transmission electron microscopy (HRTEM). Surface concentration-surface pressure (Γ-π) isotherms of the films of the capsules spread at air/buffer interface following compression-expansion show destabilizing effect on cyt c. FTIR and CD spectra of these films skimmed from the surface show that the protein transitions gradually from its native helical to an anomalous beta sheet aggregated state. This results from a competition between stabilizing hydrated polar segments of the protein in the capsule and destabilizing nonspecific hydrophobic interactions arising at the air/buffer interface. This 2D model could further our understanding of the spatial and temporal roles of proteins in confined spaces and also in the design of new drug delivery vehicles using proteins.
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Parui PP, Deshpande MS, Nagao S, Kamikubo H, Komori H, Higuchi Y, Kataoka M, Hirota S. Formation of Oligomeric Cytochrome c during Folding by Intermolecular Hydrophobic Interaction between N- and C-Terminal α-Helices. Biochemistry 2013; 52:8732-44. [DOI: 10.1021/bi400986g] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Affiliation(s)
- Partha Pratim Parui
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
- Department
of Chemistry, Jadavpur University, Kolkata 700032, India
| | - Megha Subhash Deshpande
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Satoshi Nagao
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Hironari Kamikubo
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Hirofumi Komori
- Department
of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
- RIKEN SPring-8 Center, 1-1-1
Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Yoshiki Higuchi
- Department
of Life Science, Graduate School of Life Science, University of Hyogo, 3-2-1 Koto, Kamigori-cho, Ako-gun, Hyogo 678-1297, Japan
- RIKEN SPring-8 Center, 1-1-1
Koto, Sayo-cho, Sayo-gun, Hyogo 679-5148, Japan
| | - Mikio Kataoka
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
| | - Shun Hirota
- Graduate
School of Materials Science, Nara Institute of Science and Technology, 8916-5 Takayama, Ikoma, Nara 630-0192, Japan
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Soffer JB, Fradkin E, Pandiscia LA, Schweitzer-Stenner R. The (Not Completely Irreversible) Population of a Misfolded State of Cytochrome c under Folding Conditions. Biochemistry 2013; 52:1397-408. [DOI: 10.1021/bi301586e] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Jonathan B. Soffer
- Departments of Chemistry and
Biology, Drexel University, 3141 Chestnut
Street, Philadelphia, Pennsylvania 19104, United
States
| | - Emma Fradkin
- Departments of Chemistry and
Biology, Drexel University, 3141 Chestnut
Street, Philadelphia, Pennsylvania 19104, United
States
| | - Leah A. Pandiscia
- Departments of Chemistry and
Biology, Drexel University, 3141 Chestnut
Street, Philadelphia, Pennsylvania 19104, United
States
| | - Reinhard Schweitzer-Stenner
- Departments of Chemistry and
Biology, Drexel University, 3141 Chestnut
Street, Philadelphia, Pennsylvania 19104, United
States
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Xu M, Beresneva O, Rosario R, Roder H. Microsecond folding dynamics of apomyoglobin at acidic pH. J Phys Chem B 2012; 116:7014-25. [PMID: 22475221 DOI: 10.1021/jp3012365] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Apomyolgobin (apoMb) is an important model for understanding the folding mechanism of helical proteins. This study focuses on a partially structured state of sperm whale apoMb populated at pH 4.2 (M-state), which structurally resembles a late kinetic intermediate in the formation of the native state (N) at higher pH. The thermodynamics and cooperativity of apoMb folding at pH 4.2 and 6.2 were studied by global analysis of the urea-induced unfolding transitions monitored by tryptophan fluorescence and circular dichroism. The kinetics of folding and unfolding of apoMb at pH 4.2 was measured over a time window from 40 to 850 μs, using fluorescence-detected continuous-flow measurements. Our observation of biphasic kinetics provides clear evidence for rapid (<100 μs) accumulation of previously unresolved intermediate states in both refolding and unfolding experiments. Quantitative kinetic modeling of the results, using a four-state mechanism with two intermediates on a direct route between the unfolded and folded states (U↔I↔L↔M), gave new insight into the conformational states and barriers that precede the rate-limiting step in the formation of the N-state of apoMb.
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Affiliation(s)
- Ming Xu
- Fox Chase Cancer Center, Philadelphia, Pennsylvania 19111, USA
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Use of highly purified and mixed antibodies for simultaneous detection of multiple protein species released from mitochondria upon induction of the permeability transition. Appl Biochem Biotechnol 2010; 163:64-70. [PMID: 20582638 DOI: 10.1007/s12010-010-9016-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2010] [Accepted: 06/14/2010] [Indexed: 10/19/2022]
Abstract
Concomitant with the induction of the mitochondrial permeability transition (PT), cytochrome c is released from mitochondria into the cytosol where it triggers subsequent steps of cellular apoptosis. Thus, inducers of the mitochondrial PT would become "seed compounds" of regulators of apoptosis. However, when we examine the actions of certain chemicals on the release of mitochondrial cytochrome c, the behaviors of not only cytochrome c but also multiple mitochondrial protein species must be carefully examined because the mitochondrial PT and release of proteins from mitochondria occur in diverse manners. In the present study, we examined whether it is possible to measure the behaviors of multiple protein species in a single experiment using purified and mixed antibodies. The results obtained clearly indicate that this procedure would be applicable for high-throughput screening of regulators of apoptosis. Further requirements necessary for the establishment of a useful screening system for apoptosis regulators are discussed.
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