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Chu HL, Chen HW, Tseng SH, Hsu MH, Ho LP, Chou FH, Li MPHY, Chang YC, Chen PH, Tsai LY, Chou CC, Chen JS, Cheng TM, Chang CC. Development of a growth-hormone-conjugated nanodiamond complex for cancer therapy. ChemMedChem 2014; 9:1023-9. [PMID: 24677633 DOI: 10.1002/cmdc.201300541] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2013] [Indexed: 01/28/2023]
Abstract
It is highly desirable to develop a therapeutic, observable nanoparticle complex for specific targeting in cancer therapy. Growth hormone (GH) and its antagonists have been explored as cancer cell-targeting molecules for both imaging and therapeutic applications. In this study, a low toxicity, biocompatible, therapeutic, and observable GH-nanoparticle complex for specifically targeting growth hormone receptor (GHR) in cancer cells was synthesized by conjugating GH with green fluorescence protein and carboxylated nanodiamond. Moreover, we have shown that this complex can be triggered by laser irradiation to create a "nanoblast" and induce cell death in the A549 non-small-cell lung cancer cell line via the apoptotic pathway. This laser-mediated, cancer-targeting platform can be widely used in cancer therapy.
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Affiliation(s)
- Hsueh-Liang Chu
- Department of Biological Science & Technology, National Chiao Tung, University, 75 Bo Ai Street, Hsinchu, Taiwan, 30068 (R.O.C.)
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CHANG CHIACHING, LIN CHIUSHEUN, CHEN MEICHUN, LIU YINCHANG, HUANG YIFU, LIN POYEN, CHEN YENFU, CHANG CHIASHENG, KAN LOUSING. FOLDING AND STRUCTURAL CHARACTERIZATION OF RECOMBINANT CYCLIN-DEPENDENT KINASE INHIBITOR p21(Cip1, Waf1, Sdi1). ACTA ACUST UNITED AC 2011. [DOI: 10.1142/s1793048006000070] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
p21Cip1, Waf1, Sdi1 (p21) is a member of the cyclin-dependent kinase (CDK) family of inhibitors in eukaryotes. We report the refolding of an inclusion body of a recombinant p21 (rp21) to its native form, under an alkaline to neutral environment, via an over-critical process describable by a first-order state transition model. The secondary structure of the refolded rp21 possesses a helical-major structure as determined by circular dichroism (CD) analysis, and its diameter is around 3 nm, as measured by dynamic light scattering studies (DLS) and atomic force microscopy (AFM). The differential scanning calorimeter (DSC) measurement indicates that the folded rp21 possesses unique but weak tertiary interactions. That the function of rp21 is reinstated upon refolding under our experimental conditions is evidenced by its binding to proliferating cell nuclear antigen (PCNA) in an immuno-co-precitptation analysis. The conformational changes of the folding intermediates of rp21 are consistent with the framework of a sequential model proposed earlier. The lack of a definitive structure of p21 in acidic condition will be discussed.
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Affiliation(s)
- CHIA-CHING CHANG
- Department of Physics, National Dong Hwa University, Hualien, 97401 Taiwan, ROC
| | - CHIU-SHEUN LIN
- Department of Physics, National Dong Hwa University, Hualien, 97401 Taiwan, ROC
| | - MEI-CHUN CHEN
- Department of Physics, National Dong Hwa University, Hualien, 97401 Taiwan, ROC
| | - YIN-CHANG LIU
- Department of Life Science and Institute of Molecular Medicine, National Tsing-Hua University, Hsin-Chu, 30043 Taiwan, ROC
| | - YI-FU HUANG
- Department of Life Science and Institute of Molecular Medicine, National Tsing-Hua University, Hsin-Chu, 30043 Taiwan, ROC
| | - PO-YEN LIN
- Institute of Physics, Academia Sinica, Taipei, 11529 Taiwan, ROC
| | - YEN-FU CHEN
- Institute of Physics, Academia Sinica, Taipei, 11529 Taiwan, ROC
| | - CHIA-SHENG CHANG
- Institute of Physics, Academia Sinica, Taipei, 11529 Taiwan, ROC
| | - LOU-SING KAN
- Institute of Chemistry, Academia Sinica, Taipei, 11529 Taiwan, ROC
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Chang CC, Lin PY, Yeh XC, Deng KH, Ho YP, Kan LS. Protein folding stabilizing time measurement: A direct folding process and three-dimensional random walk simulation. Biochem Biophys Res Commun 2005; 328:845-50. [PMID: 15707956 DOI: 10.1016/j.bbrc.2005.01.036] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2004] [Indexed: 11/28/2022]
Abstract
Protein particles undergo Brownian motion and collisions in solution. The diffusive collisions may lead to aggregation. For proteins to fold successfully the process has to occur quickly and before significant collision takes place. The speed of protein folding was deduced by studying the correlation time of a lysozyme refolding process from autocorrelation function analysis of the mean collision time and aggregation/soluble ratio of protein. It is a measure of time before which an aggregate can be formed and also is the time measure for a protein to fold into a stable state. We report on the protein folding stabilizing time of a lysozyme system to be 25.5-27.5 micros (<+/-4%) between 295 and 279K via direct folding experimental studies, supported by a three-dimensional random walk simulation of diffusion-limited aggregation model. Aggregation is suppressed when the protein is folded to a stable form. Spontaneous folding and diffusion-limited aggregation are antagonistic in nature. Meanwhile, the resultant aggresome, suggested by Raman and mass spectroscopy, may be formed by cross-linkages of disulfide bonds and hydrophobic interactions.
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Affiliation(s)
- Chia-Ching Chang
- Department of Physics, National Dong Hwa University, Hualien 97401, Taiwan.
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Chang CC, Yeh XC, Lee HT, Lin PY, Kan LS. Refolding of lysozyme by quasistatic and direct dilution reaction paths: a first-order-like state transition. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2004; 70:011904. [PMID: 15324085 DOI: 10.1103/physreve.70.011904] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/06/2003] [Indexed: 05/24/2023]
Abstract
A first-order-like state transition model is considered to be a global reaction mechanism to directly folded proteins from an unfolded state to its native form. In order to verify the general applicability of this mechanism, we used lysozyme as a model protein. It was fully unfolded by 4.5 M urea, 0.1 M dithiothreitol (DTT) in pH 3 and refolded to its native form by way of an overcritical reaction path (a quasistatic process) or directly crossing transition boundary path (a directly dilution process). In addition to the two states coexisting in the direct folding path, lysozyme might be trapped in a glassy state. However, it can escape from the glassy state by concentration twice. This indicates the existence of a state transition line or boundary in the direct folding reaction. However, lysozyme can continuously fold from unfolded to native by an overcritical reaction path. During the overcritical path, four stable folding intermediates and native lysozyme were obtained. The secondary structures, particle size distributions, thermal stabilities, and oxidation state of disulfide bonds of folding intermediates were analyzed by circular dichroism spectra, dynamic light scattering, differential scanning calorimetry, and Raman spectra, respectively. According to the data, the intermediates of both the overcritical reaction and the direct crossing transition boundary paths can be described by a common concept pertaining to a model that undergoes collapse, sequential, and first-order-like state transition. This indicated that protein folding by way of different reaction paths might follow a similar folding mechanism-i.e., a mechanism of overcritical folding of intermediates. A protein folding reaction diagram is postulated and discussed. In spite of a global interaction mechanism the alpha -helix is formed prior to the beta -sheet, which may indicate that protein folding is initiated by local interactions.
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Affiliation(s)
- Chia-Ching Chang
- Department of Physics, National Dong Hwa University, Hualien, Taiwan 97401.
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Chang CC, Cheng MS, Su YC, Kan LS. A first-order-like state transition for recombinant protein folding. J Biomol Struct Dyn 2003; 21:247-56. [PMID: 12956608 DOI: 10.1080/07391102.2003.10506920] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Normally, proteins will aggregate and precipitate by direct folding processes. In this study, we report that quasi-static processes can restore both the structure and bio-function of two kinds of fish recombinant growth hormones (Plecoglossus altivelis and Epinephelus awoara). The conformational changes and the particle-size-distribution (PSD) of each refolding intermediate can be monitored by circular dichroism spectroscopy (CD) and dynamic light scattering (DLS), respectively. Conformation analysis of the CD spectra of the refolding intermediates indicated that the secondary structures were restored in the initial refolding intermediate. However, the tertiary interactions of the proteins were restored during the last two refolding stages, as elucidated by thermal stability tests. This is consistent with a sequential model. DLS analysis suggested that the average hydrodynamic radii of the refolding intermediates shrank to their native-like sizes after the first refolding stage. This is consistent with a collapse model. After comparison with the data on the direct folding process, it is concluded that the denaturant-containing protein folding reaction is a first-order-like state transition process.
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Affiliation(s)
- Chia-Ching Chang
- Department of Physics, National Dong Hwa University,Hualien, Taiwan 97401.
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Liu YL, Lee HT, Chang CC, Kan LS. Reversible folding of cysteine-rich metallothionein by an overcritical reaction path. Biochem Biophys Res Commun 2003; 306:59-63. [PMID: 12788066 DOI: 10.1016/s0006-291x(03)00899-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
A first-order-like state transition is considered to be involved in the restoration of the activities of a few proteins by correctly folding the protein [Phys. Rev. E 66 (2002) 021903]. In order to understand the general applicability of this mechanism, we studied a metallothionein (MT) protein with an unconventional structure, i.e., without any alpha-helix or beta-sheet. MT is a 61 amino-acid peptide. There are 6-7 Zn(2+) ions, which bind avidly to 20 conserved cysteines (Cys) of MT. These properties indicate that the structure of MT is quite different from those of the other proteins. Similar to our previous findings, the denatured MT can be folded without any aggregation via a designated stepwise quasi-static process (an over-critical reaction path). The particle size of folded MT intermediates, determined by dynamic light scattering, shrank right after the first folding stage. It is consistent with a collapse-model. In addition, results from both atomic absorption and circular dichroism (CD) indicate that the stable intermediates may fold to the native conformation but with only partial Zn(2+) binding, which in turn implies that those folding intermediates are in a molten globular state. These reversible unfolding and folding processes indicate that Cys-rich protein, MT, may also be folded by way of a first-order-like state transition mechanism. We suspect that this process may likely be involved in the reaction of the metal substitution process in metal containing enzymes.
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Affiliation(s)
- Yi-Liang Liu
- Department of Physics, National Dong Hwa University, 97401, ROC, Hualien, Taiwan
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Chang CC, Su YC, Cheng MS, Kan LS. Protein folding by a quasi-static-like process: a first-order state transition. PHYSICAL REVIEW. E, STATISTICAL, NONLINEAR, AND SOFT MATTER PHYSICS 2002; 66:021903. [PMID: 12241210 DOI: 10.1103/physreve.66.021903] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/29/2002] [Indexed: 05/23/2023]
Abstract
In this paper we report that quasi-static-like processes, in which stable intermediates were introduced carefully and deliberately, may be used to reversibly unfold and refold purified native porcine growth hormone. Through circular dichroism (CD) and dynamic light scattering (DLS), we were able to study the secondary structure conformational changes, tertiary structure thermal stabilities, and the particle size distributions of both the intermediates and the final folded product. The CD data showed that the secondary structure was restored in the initial folding stage, whereas the tertiary structure within the protein was restored one step before the last folding stage, as elucidated by thermal stability experiments. DLS analysis suggested that the average hydrodynamic radii of the folding intermediates shrunk to nativelike size immediately after the first folding stage. Our data suggested that the denaturant-containing protein folding reaction is a first-order-like state transition process. This quasi-static-like process may be useful in the prevention of aggregate formation in protein purification and thus can be used in protein engineering to improve the overall yield from harvesting proteins.
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Affiliation(s)
- Chia-Ching Chang
- Department of Physics, National Dong Hwa University, Hualien, Taiwan 97401.
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