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Jin Y, Yu G, Yuwen T, Gao D, Wang G, Zhou Y, Jiang B, Zhang X, Li C, He L, Liu M. Molecular Insight into the Extracellular Chaperone Serum Albumin in Modifying the Folding Free Energy Landscape of Client Proteins. J Phys Chem Lett 2022; 13:2711-2717. [PMID: 35311276 DOI: 10.1021/acs.jpclett.2c00265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Serum albumin (SA) is the most abundant extracellular chaperone protein presenting in various bodily fluids. Recently, several studies have revealed molecular mechanisms of SA in preventing the amyloid formation of amyloidogenic proteins. However, our insight into the mechanism SA employed to sense and regulate the folding states of full-length native proteins is still limited. Addressing this question is technically challenging due to the intrinsic dynamic nature of both chaperones and clients. Here using nuclear magnetic resonance spectroscopy, we show SA modifies the folding free energy landscape of clients and subsequently alters the equilibria between different compact conformations of its clients, resulting in the increased populations of excited states of client proteins. This modulation of client protein conformation by SA can change the client protein activity in a way that cannot be interpreted on the basis of its ground state structure; therefore, our work provides an alternative insight of SA in retaining a balanced functional proteome.
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Affiliation(s)
- Yangzhuoyue Jin
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Gangjin Yu
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Tairan Yuwen
- Department of Pharmaceutical Analysis & State Key Laboratory of Natural and Biomimetic Drugs, School of Pharmaceutical Sciences, Peking University, Beijing 100871, China
| | - Dawei Gao
- State Key Laboratory of Metastable Materials Science and Technology, Yanshan University, Hebei 066004, China
| | - Guan Wang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yilin Zhou
- College of Chemistry, Central China Normal University, Wuhan 430079, China
| | - Bin Jiang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xu Zhang
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Conggang Li
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Lichun He
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Maili Liu
- State Key Laboratory of Magnetic Resonance and Atomic Molecular Physics, National Center for Magnetic Resonance in Wuhan, Innovation Academy for Precision Measurement Science and Technology, Chinese Academy of Sciences, Hubei 430071, China
- University of Chinese Academy of Sciences, Beijing 100049, China
- Optics Valley Laboratory, Hubei 430074, China
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2
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Jain N, Knowles TJ, Lund PA, Chaudhuri TK. Minichaperone (GroEL191-345) mediated folding of MalZ proceeds by binding and release of native and functional intermediates. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2018; 1866:941-951. [PMID: 29864530 DOI: 10.1016/j.bbapap.2018.05.015] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 05/02/2018] [Accepted: 05/28/2018] [Indexed: 10/14/2022]
Abstract
The isolated apical domain of GroEL consisting of residues 191-345 (known as "minichaperone") binds and assists the folding of a wide variety of client proteins without GroES and ATP, but the mechanism of its action is still unknown. In order to probe into the matter, we have examined minichaperone-mediated folding of a large aggregation prone protein Maltodextrin-glucosidase (MalZ). The key objective was to identify whether MalZ exists free in solution, or remains bound to, or cycling on and off the minichaperone during the refolding process. When GroES was introduced during refolding process, production of the native MalZ was inhibited. We also observed the same findings with a trap mutant of GroEL, which stably captures a predominantly non-native MalZ released from minichaperone during refolding process, but does not release it. Tryptophan and ANS fluorescence measurements indicated that refolded MalZ has the same structure as the native MalZ, but that its structure when bound to minichaperone is different. Surface plasmon resonance measurements provide an estimate for the equilibrium dissociation constant KD for the MalZ-minichaperone complex of 0.21 ± 0.04 μM, which are significantly higher than for most GroEL clients. This showed that minichaperone interacts loosely with MalZ to allow the protein to change its conformation and fold while bound during the refolding process. These observations suggest that the minichaperone works by carrying out repeated cycles of binding aggregation-prone protein MalZ in a relatively compact conformation and in a partially folded but active state, and releasing them to attempt to fold in solution.
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Affiliation(s)
- Neha Jain
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India; Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, UK
| | - Timothy J Knowles
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, UK
| | - Peter A Lund
- Institute of Microbiology and Infection, School of Biosciences, University of Birmingham, UK.
| | - Tapan K Chaudhuri
- Kusuma School of Biological Sciences, Indian Institute of Technology Delhi, India.
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Singh A, Abd AJ, Al-Mashahedah A, Kanwar JR. Corneal Haze, Refractive Surgery, and Implications for Choroidal Neovascularization. DRUG DELIVERY FOR THE RETINA AND POSTERIOR SEGMENT DISEASE 2018:439-477. [DOI: 10.1007/978-3-319-95807-1_25] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
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4
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A study on human serum albumin influence on glycation of fibrinogen. Biochem Biophys Res Commun 2013; 439:78-83. [PMID: 23958299 DOI: 10.1016/j.bbrc.2013.08.025] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2013] [Accepted: 08/08/2013] [Indexed: 11/23/2022]
Abstract
Although in vivo glycation proceeds in complex mixture of proteins, previous studies did not take in consideration the influence of protein-protein interaction on Maillard reaction. The aim of our study was to test the influence of human serum albumin (HSA) on glycation of fibrinogen. The isotopic labeling using [(13)C6] glucose combined with LC-MS were applied as tool for identification possible glycation sites in fibrinogen and for evaluation the effect of HSA on the glycation level of selected amino acids in fibrinogen. The obtained data indicate that the addition of HSA protects the fibrinogen from glycation. The level of glycation in presence of HSA is reduced by 30-60% and depends on the location of glycated residue in sequence of protein.
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5
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Lin CY, Liu YC, Lin MC, Thi Nguyen T, Tam MF, Chein CY, Lin MT, Lin LY. Expression and characterization of SUMO-conjugated metal-responsive transcription factor 1: SIM-dependent cross-interaction and distinct DNA binding activity. J Biochem 2013; 153:361-9. [PMID: 23347955 DOI: 10.1093/jb/mvt002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Metal-responsive transcription factor 1 (MTF-1) regulates a variety of genes involving in metal homeostasis and oxidative stress. We have shown that MTF-1 can be conjugated by small ubiquitin-like modifier (SUMO) and forms complexes with cellular factor(s) in a SUMO-interacting motif (SIM)-dependent manner. To investigate whether the interaction of MTF-1 and its SUMO conjugate occurs, we expressed and isolated MTF-1 and sumoylated MTF-1 (S-MTF-1) for functional studies. Various conditions were examined to optimize the expressions of MTF-1 and S-MTF-1. Results from affinity column chromatography demonstrated that the unmodified MTF-1 consistently co-eluted with the S-MTF-1. Mutations at the SIM did not reduce the level of MTF-1 sumoylation but the sumoylated product can then be purified to homogeneity. The presence of MTF-1 cross-interaction was further supported by in vitro pull-down assays. The ability of the purified proteins in binding metal-responsive element (MRE) was assessed with electrophoretic mobility shift assay. Noticeably, MTF-1 required the presence of cell extracts to render the binding activity. However, S-MTF-1 binds MRE in void of other cellular factors. The same characteristic was found for MTF-1 with SUMO fusion at the carboxyl terminus. These results indicate that the presence of SUMO moiety allows the protein to interact directly with MRE.
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Affiliation(s)
- Chang-Yi Lin
- Institute of Molecular and Cellular Biology and Department of Life Science, National Tsing Hua University, No. 101, Section 2, Kuang-Fu Road, Hsinchu 30013, Taiwan
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6
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Roles of Extracellular Chaperones in Amyloidosis. J Mol Biol 2012; 421:499-516. [DOI: 10.1016/j.jmb.2012.01.004] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2011] [Revised: 01/02/2012] [Accepted: 01/03/2012] [Indexed: 01/24/2023]
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7
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Jewett AI, Shea JE. Reconciling theories of chaperonin accelerated folding with experimental evidence. Cell Mol Life Sci 2010; 67:255-76. [PMID: 19851829 PMCID: PMC11115962 DOI: 10.1007/s00018-009-0164-6] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2009] [Revised: 09/14/2009] [Accepted: 09/25/2009] [Indexed: 10/20/2022]
Abstract
For the last 20 years, a large volume of experimental and theoretical work has been undertaken to understand how chaperones like GroEL can assist protein folding in the cell. The most accepted explanation appears to be the simplest: GroEL, like most other chaperones, helps proteins fold by preventing aggregation. However, evidence suggests that, under some conditions, GroEL can play a more active role by accelerating protein folding. A large number of models have been proposed to explain how this could occur. Focused experiments have been designed and carried out using different protein substrates with conclusions that support many different mechanisms. In the current article, we attempt to see the forest through the trees. We review all suggested mechanisms for chaperonin-mediated folding and weigh the plausibility of each in light of what we now know about the most stringent, essential, GroEL-dependent protein substrates.
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Affiliation(s)
- Andrew I. Jewett
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106 USA
- Department of Physics, University of California, Santa Barbara, CA 93106 USA
| | - Joan-Emma Shea
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106 USA
- Department of Physics, University of California, Santa Barbara, CA 93106 USA
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8
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The role of corneal crystallins in the cellular defense mechanisms against oxidative stress. Semin Cell Dev Biol 2007; 19:100-12. [PMID: 18077195 DOI: 10.1016/j.semcdb.2007.10.004] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2007] [Accepted: 10/04/2007] [Indexed: 11/19/2022]
Abstract
The refracton hypothesis describes the lens and cornea together as a functional unit that provides the proper ocular transparent and refractive properties for the basis of normal vision. Similarities between the lens and corneal crystallins also suggest that both elements of the refracton may also contribute to the antioxidant defenses of the entire eye. The cornea is the primary physical barrier against environmental assault to the eye and functions as a dominant filter of UV radiation. It is routinely exposed to reactive oxygen species (ROS)-generating UV light and molecular O(2) making it a target vulnerable to UV-induced damage. The cornea is equipped with several defensive mechanisms to counteract the deleterious effects of UV-induced oxidative damage. These comprise both non-enzymatic elements that include proteins and low molecular weight compounds (ferritin, glutathione, NAD(P)H, ascorbate and alpha-tocopherol) as well as various enzymes (catalase, glucose-6-phosphate dehydrogenase, glutathione peroxidase, glutathione reductase, and superoxide dismutase). Several proteins accumulate in the cornea at unusually high concentrations and have been classified as corneal crystallins based on the analogy of these proteins with the abundant taxon-specific lens crystallins. In addition to performing a structural role related to ocular transparency, corneal crystallins may also contribute to the corneal antioxidant systems through a variety of mechanisms including the direct scavenging of free radicals, the production of NAD(P)H, the metabolism and/or detoxification of toxic compounds (i.e. reactive aldehydes), and the direct absorption of UV radiation. In this review, we extend the discussion of the antioxidant defenses of the cornea to include these highly expressed corneal crystallins and address their specific capacities to minimize oxidative damage.
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9
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Jewett AI, Shea JE. Folding on the chaperone: yield enhancement through loose binding. J Mol Biol 2006; 363:945-57. [PMID: 16987526 DOI: 10.1016/j.jmb.2006.08.040] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2006] [Revised: 07/28/2006] [Accepted: 08/16/2006] [Indexed: 10/24/2022]
Abstract
A variety of small cageless chaperones have been discovered that can assist protein folding without the consumption of ATP. These include mini-chaperones (catalytically active fragments of larger chaperones), as well as small proteins such as alpha-casein and detergents acting as "artificial chaperones." These chaperones all possess exposed hydrophobic patches on their surface that act as recognition sites for misfolded proteins. They lack the complexity of chaperonins (that encapsulate proteins in their inner rings) and their study can offer insight into the minimal requirements for chaperone function. We use molecular dynamics simulations to investigate how a cageless chaperone, modeled as a sphere of tunable hydrophobicity, can assist folding of a substrate protein. We find that under steady-state (non-stress) conditions, cageless chaperones that bind to a single substrate protein increase folding yields by reducing the time the substrate spends in an aggregation-prone state in a dual manner: (a) by competing for aggregation-prone hydrophobic sites on the surface of a protein, hence reducing the time the protein spends unprotected in the bulk and (b) by accelerating folding rates of the protein. In both cases, the chaperone must bind to and hold the protein loosely enough to allow the protein to change its conformation and fold while bound. Loose binding may enable small cageless chaperones to help proteins fold and avoid aggregation under steady-state conditions, even at low concentrations, without the consumption of ATP.
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Affiliation(s)
- A I Jewett
- Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93106, USA
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10
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Melkani GC, Cammarato A, Bernstein SI. αB-Crystallin Maintains Skeletal Muscle Myosin Enzymatic Activity and Prevents its Aggregation under Heat-shock Stress. J Mol Biol 2006; 358:635-45. [PMID: 16546210 DOI: 10.1016/j.jmb.2006.02.043] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2005] [Revised: 02/13/2006] [Accepted: 02/15/2006] [Indexed: 11/23/2022]
Abstract
Here, we provide functional and direct structural evidence that alphaB-crystallin, a member of the small heat-shock protein family, suppresses thermal unfolding and aggregation of the myosin II molecular motor. Chicken skeletal muscle myosin was thermally unfolded at heat-shock temperature (43 degrees C) in the absence and in the presence of alphaB-crystallin. The ATPase activity of myosin at 25 degrees C was used as a parameter to monitor its unfolding. Myosin retained only 65% and 8% of its ATPase activity when incubated at heat-shock temperature for 15 min and 30 min, respectively. However, 84% and 58% of the myosin ATPase activity was maintained when it was incubated with alphaB-crystallin under the same conditions. Furthermore, actin-stimulated ATPase activity of myosin was reduced by approximately 90%, when myosin was thermally unfolded at 43 degrees C for 30 min, but was reduced by only approximately 42% when it was incubated with alphaB-crystallin under the same conditions. Light-scattering assays and bound thioflavin T fluorescence indicated that myosin aggregates when incubated at 43 degrees C for 30 min, while alphaB-crystallin suppressed this thermal aggregation. Photo-labeled bis-ANS alphaB-crystallin fluorescence studies confirmed the transient interaction of alphaB-crystallin with myosin. These findings were further supported by electron microscopy of rotary shadowed molecules. This revealed that approximately 94% of myosin molecules formed inter and intra-molecular aggregates when incubated at 43 degrees C for 30 min. alphaB-Crystallin, however, protected approximately 48% of the myosin molecules from thermal aggregation, with protected myosin appearing identical to unheated molecules. These results are the first to show that alphaB-crystallin maintains myosin enzymatic activity and prevents the aggregation of the motor under heat-shock conditions. Thus, alphaB-crystallin may be critical for nascent myosin folding, promoting myofibrillogenesis, maintaining cytoskeletal integrity and sustaining muscle performance, since heat-shock temperatures can be produced during multiple stress conditions or vigorous exercise.
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Affiliation(s)
- Girish C Melkani
- Department of Biology and the Molecular Biology Institute, San Diego State University, 5550 Campanile Drive, San Diego, CA 92182-4614, USA
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11
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Goenka S, Raman B, Ramakrishna T, Rao CM. Unfolding and refolding of a quinone oxidoreductase: alpha-crystallin, a molecular chaperone, assists its reactivation. Biochem J 2001; 359:547-56. [PMID: 11672428 PMCID: PMC1222175 DOI: 10.1042/0264-6021:3590547] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
alpha-Crystallin, a member of the small heat-shock protein family and present in vertebrate eye lens, is known to prevent the aggregation of other proteins under conditions of stress. However, its role in the reactivation of enzymes from their non-native inactive states has not been clearly demonstrated. We have studied the effect of alpha-crystallin on the refolding of zeta-crystallin, a quinone oxidoreductase, from its different urea-denatured states. Co-refolding zeta-crystallin from its denatured state in 2.5 M urea with either calf eye lens alpha-crystallin or recombinant human alpha B-crystallin could significantly enhance its reactivation yield. alpha B-crystallin was found to be more efficient than alpha A-crystallin in chaperoning the refolding of zeta-crystallin. In order to understand the nature of the denatured state(s) of zeta-crystallin that can interact with alpha-crystallin, we have investigated the unfolding pathway of zeta-crystallin. We find that it unfolds through three distinct intermediates: an altered tetramer, a partially unfolded dimer, which is competent to fold back to its active state, and a partially unfolded monomer. The partially unfolded monomer is inactive, exhibits highly exposed hydrophobic surfaces and has significant secondary structural elements with little or no tertiary structure. This intermediate does not refold into the active state without assistance. alpha-Crystallin provides the required assistance and improves the reactivation yield several-fold.
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Affiliation(s)
- S Goenka
- Centre for Cellular and Molecular Biology, Uppal Road, Hyderabad, 500 007, India
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12
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Smoot AL, Panda M, Brazil BT, Buckle AM, Fersht AR, Horowitz PM. The binding of bis-ANS to the isolated GroEL apical domain fragment induces the formation of a folding intermediate with increased hydrophobic surface not observed in tetradecameric GroEL. Biochemistry 2001; 40:4484-92. [PMID: 11284705 DOI: 10.1021/bi001822b] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The extent of hydrophobic exposure upon bis-ANS binding to the functional apical domain fragment of GroEL, or minichaperone (residues 191-345), was investigated and compared with that of the GroEL tetradecamer. Although a total of seven molecules of bis-ANS bind cooperatively to this minichaperone, most of the hydrophobic sites were induced following initial binding of one to two molecules of probe. From the equilibrium and kinetics studies at low bis-ANS concentrations, it is evident that the native apical domain is converted to an intermediate conformation with increased hydrophobic surfaces. This intermediate binds additional bis-ANS molecules. Tyrosine fluorescence detected denaturation demonstrated that bis-ANS can destabilize the apical domain. The results from (i) bis-ANS titrations, (ii) urea denaturation studies in the presence and absence of bis-ANS, and (iii) intrinsic tyrosine fluorescence studies of the apical domain are consistent with a model in which bis-ANS binds tightly to the intermediate state, relatively weakly to the native state, and little to the denatured state. The results suggest that the conformational changes seen in apical domain fragments are not seen in the intact GroEL oligomer due to restrictions imposed by connections of the apical domain to the intermediate domain and suppression of movement due to quaternary structure.
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Affiliation(s)
- A L Smoot
- Department of Biochemistry, University of Texas Health Science Center at San Antonio, San Antonio, Texas 78229-3900, USA
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13
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Wang JD, Michelitsch MD, Weissman JS. GroEL-GroES-mediated protein folding requires an intact central cavity. Proc Natl Acad Sci U S A 1998; 95:12163-8. [PMID: 9770457 PMCID: PMC22802 DOI: 10.1073/pnas.95.21.12163] [Citation(s) in RCA: 49] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The chaperonin GroEL is an oligomeric double ring structure that, together with the cochaperonin GroES, assists protein folding. Biochemical analyses indicate that folding occurs in a cis ternary complex in which substrate is sequestered within the GroEL central cavity underneath GroES. Recently, however, studies of GroEL "minichaperones" containing only the apical substrate binding subdomain have questioned the functional importance of substrate encapsulation within GroEL-GroES complexes. Minichaperones were reported to assist folding despite the fact that they are monomeric and therefore cannot form a central cavity. Here we compare directly the folding activity of minichaperones with that of the full GroEL-GroES system. In agreement with earlier studies, minichaperones assist folding of some proteins. However, this effect is observed only under conditions where substantial spontaneous folding is also observed and is indistinguishable from that resulting from addition of the nonchaperone protein alpha-casein. By contrast, the full GroE system efficiently promotes folding of several substrates under conditions where essentially no spontaneous folding is observed. These data argue that the full GroEL folding activity requires the intact GroEL-GroES complex, and in light of previous studies, underscore the importance of substrate encapsulation for providing a folding environment distinct from the bulk solution.
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Affiliation(s)
- J D Wang
- Department of Pharmacology, University of California-San Francisco, 513 Parnassus Avenue, San Francisco, CA 94143-0450, USA
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14
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Kudlicki W, Coffman A, Kramer G, Hardesty B. Renaturation of rhodanese by translational elongation factor (EF) Tu. Protein refolding by EF-Tu flexing. J Biol Chem 1997; 272:32206-10. [PMID: 9405422 DOI: 10.1074/jbc.272.51.32206] [Citation(s) in RCA: 74] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
The translation elongation factor (EF) Tu has chaperone-like capacity to promote renaturation of denatured rhodanese. This renaturation activity is greatly increased under conditions in which the factor can oscillate between the open and closed conformations that are induced by GDP and GTP, respectively. Oscillation occurs during GTP hydrolysis and subsequent replacement of GDP by EF-Ts which is then displaced by GTP. Renaturation of rhodanese and GTP hydrolysis by EF-Tu are greatly enhanced by the guanine nucleotide exchange factor EF-Ts. However, renaturation is reduced under conditions that stabilize EF-Tu in either the open or closed conformation. Both GDP and the nonhydrolyzable analog of GTP, GMP-PCP, inhibit renaturation. Kirromycin and pulvomycin, antibiotics that specifically bind to EF-Tu and inhibit its activity in peptide elongation, also strongly inhibit EF-Tu-mediated renaturation of denatured rhodanese to levels near those observed for spontaneous, unassisted refolding. Kirromycin locks EF-Tu in the open conformation in the presence of either GTP or GDP, whereas pulvomycin locks the factor in the closed conformation. The results lead to the conclusion that flexing of EF-Tu, especially as occurs between its open and closed conformations, is a major factor in its chaperone-like refolding activity.
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Affiliation(s)
- W Kudlicki
- Molecular Biology Institute and the Department of Chemistry & Biochemistry, The University of Texas, Austin, Texas 78712, USA
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15
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Schmitz JP, Zardeneta G, Agrawal CM, Lee T, Athanasiou K, Milam SB. Protein Interactions with Polylactide-Polyglycolide Particles and Scaffolds. ACTA ACUST UNITED AC 1997. [DOI: 10.1089/ten.1997.3.257] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Affiliation(s)
- John P. Schmitz
- South Texas Tissue Engineering Group, The University of Texas Health Science Center at San Antonio, Department of Oral and Maxillo-Facial Surgery, San Antonio, Texas 78284
| | - Gustavo Zardeneta
- South Texas Tissue Engineering Group, The University of Texas Health Science Center at San Antonio, Department of Oral and Maxillo-Facial Surgery, San Antonio, Texas 78284
| | - C. Mauli Agrawal
- South Texas Tissue Engineering Group, The University of Texas Health Science Center at San Antonio, Department of Orthopaedics, San Antonio, Texas 78284
| | - Tim Lee
- South Texas Tissue Engineering Group, The University of Texas Health Science Center at San Antonio, third-year medical student, San Antonio, Texas 78284
| | - Kyriacos Athanasiou
- South Texas Tissue Engineering Group, The University of Texas Health Science Center at San Antonio, Department of Orthopaedics, San Antonio, Texas 78284
| | - Stephen B. Milam
- South Texas Tissue Engineering Group, The University of Texas Health Science Center at San Antonio, Department of Oral and Maxillo-Facial Surgery, San Antonio, Texas 78284
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16
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Mendoza J, Demeler B, Horowitz P. Alteration of the quaternary structure of cpn60 modulates chaperonin-assisted folding. Implications for the mechanism of chaperonin action. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)41966-1] [Citation(s) in RCA: 52] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
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17
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Abstract
Recent advances in protein expression in E. coli have focused primarily on the enhancement of protein quality. Problems in mRNA translation such as inefficient initiation, mistranslation, frame-shifting and frame-hopping can often be addressed by altering heterologous gene-coding sequences. Fusion technology can also be used to address problems in translational initiation, the authenticity of amino-terminal amino acids, in vivo protein activity and protein purification. Accessory molecules, such as chaperones, are increasingly used to enhance protein quality in vivo and in vitro. E. coli has recently gained wide use as a host both for the engineering of proteins with altered activities and for the creation of multi-functional hybrids.
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Affiliation(s)
- P O Olins
- Monsanto Corporate Research, Monsanto Company, St. Louis, Missouri 63198
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