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Dirak M, Chan J, Kolemen S. Optical imaging probes for selective detection of butyrylcholinesterase. J Mater Chem B 2024; 12:1149-1167. [PMID: 38196348 DOI: 10.1039/d3tb02468g] [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: 01/11/2024]
Abstract
Butyrylcholinesterase (BChE), a member of the human serine hydrolase family, is an essential enzyme for cholinergic neurotransmission as it catalyzes the hydrolysis of acetylcholine. It also plays central roles in apoptosis, lipid metabolism, and xenobiotic detoxification. On the other side, abnormal levels of BChE are directly associated with the formation of pathogenic states such as neurodegenerative diseases, psychiatric and cardiovascular disorders, liver damage, diabetes, and cancer. Thus, selective and sensitive detection of BChE level in living organisms is highly crucial and is of great importance to further understand the roles of BChE in both physiological and pathological processes. However, it is a very complicated task due to the potential interference of acetylcholinesterase (AChE), the other human cholinesterase, as these two enzymes share a very similar substrate scope. To this end, optical imaging probes have attracted immense attention in recent years as they have modular structures, which can be tuned precisely to satisfy high selectivity toward BChE, and at the same time they offer real time and nondestructive imaging opportunities with a high spatial and temporal resolution. Here, we summarize BChE selective imaging probes by discussing the critical milestones achieved during the development process of these molecular sensors over the years. We put a special emphasis on design principles and biological applications of highly promising new generation activity-based probes. We also give a comprehensive outlook for the future of BChE-responsive probes and highlight the ongoing challenges. This collection marks the first review article on BChE-responsive imaging agents.
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Affiliation(s)
- Musa Dirak
- Department of Chemistry, Koç University, 34450 Istanbul, Turkey.
| | - Jefferson Chan
- Department of Chemistry, Beckman Institute for Advanced Science and Technology, and Cancer Center at Illinois, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | - Safacan Kolemen
- Department of Chemistry, Koç University, 34450 Istanbul, Turkey.
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Abstract
Vitrification is an alternative to cryopreservation by freezing that enables hydrated living cells to be cooled to cryogenic temperatures in the absence of ice. Vitrification simplifies and frequently improves cryopreservation because it eliminates mechanical injury from ice, eliminates the need to find optimal cooling and warming rates, eliminates the importance of differing optimal cooling and warming rates for cells in mixed cell type populations, eliminates the need to find a frequently imperfect compromise between solution effects injury and intracellular ice formation, and can enable chilling injury to be "outrun" by using rapid cooling without a risk of intracellular ice formation. On the other hand, vitrification requires much higher concentrations of cryoprotectants than cryopreservation by freezing, which introduces greater risks of both osmotic damage and cryoprotectant toxicity. Fortunately, a large number of remedies for the latter problem have been discovered over the past 35 years, and osmotic damage can in most cases be eliminated or adequately controlled by paying careful attention to cryoprotectant introduction and washout techniques. Vitrification therefore has the potential to enable the superior and convenient cryopreservation of a wide range of biological systems (including molecules, cells, tissues, organs, and even some whole organisms), and it is also increasingly recognized as a successful strategy for surviving harsh environmental conditions in nature. But the potential of vitrification is sometimes limited by an insufficient understanding of the complex physical and biological principles involved, and therefore a better understanding may not only help to improve present outcomes but may also point the way to new strategies that may be yet more successful in the future. This chapter accordingly describes the basic principles of vitrification and indicates the broad potential biological relevance of this alternative method of cryopreservation.
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Yasuda S, Kazama K, Akiyama T, Kinoshita M, Murata T. Elucidation of cosolvent effects thermostabilizing water-soluble and membrane proteins. J Mol Liq 2020. [DOI: 10.1016/j.molliq.2019.112403] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
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Costa RDS, Capuzzo CDS, Ribeiro CDS, Verissimo-Silveira R, Siqueira-Silva DHD, Senhorini JA, Ninhaus-Silveira A. Morphological evaluation of Prochilodus lineatus embryos after vitrification-thawing in high-osmolarity cryoprotectant solution. Reprod Domest Anim 2018; 53:1353-1358. [PMID: 30011097 DOI: 10.1111/rda.13249] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 06/12/2018] [Indexed: 11/30/2022]
Abstract
We aimed to vitrify embryos of Prochilodus lineatus in a high-osmolarity cryoprotectant solution, evaluating, after the vitrification-thawing process, their morphological changes. Thus, 240 embryos in the 20-somite phase (20S) were exposed for 20 min to one main internal cryoprotectant solution (1,2-propanediol-PROP), divided into four immersion sequence steps of five minutes each. The first three steps were performed in solutions containing only a main internal cryoprotectant (PROP-2, 3 and 4 M), and the fourth step in a high-osmolarity solution combining internal (PROP + dimethyl sulphoxide-Me2 SO) and external cryoprotectants (sucrose-SUC). The final concentration of vitrification was PROP 5 M + Me2 SO 5 M + SUC 0.2 M. During vitrification, the straws exhibited a translucent solid appearance; however, during thawing, their structure became totally opaque and white. After thawing, the embryos suffered an increase in volume and presented morphological changes including protrusions on the surface of the yolk sac, yolk sac rupture, and optical vesicle degradation. On the inside, we observed intercellular spaces and a yolk syncytial layer (YSL) with altered chromatin. Yet, structures such as somites, neural tube, endoderm and epidermis presented cells with a nucleus and integral mitochondria. We conclude that the use of the tested cryoprotectant solution permits the formation of a vitreous solid and preserves part of the cells of the blastoderm. Yet, the heating protocol does not control recrystallization, resulting in the formation of serious morphological anomalies that prevent the preservation of the embryonic unit.
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Affiliation(s)
- Raphael da Silva Costa
- Department of Biology and Animal Science, Universidade Estadual Paulista "Júlio de Mesquita Filho", Ilha Solteira, Brazil.,Pós-Graduação em Biologia Animal, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, Brazil
| | - Caio de Souza Capuzzo
- Department of Biology and Animal Science, Universidade Estadual Paulista "Júlio de Mesquita Filho", Ilha Solteira, Brazil
| | - Cristiele da Silva Ribeiro
- Department of Biology and Animal Science, Universidade Estadual Paulista "Júlio de Mesquita Filho", Ilha Solteira, Brazil
| | - Rosicleire Verissimo-Silveira
- Department of Biology and Animal Science, Universidade Estadual Paulista "Júlio de Mesquita Filho", Ilha Solteira, Brazil
| | | | - José Augusto Senhorini
- National Center for Research and Conservation of Continental Fish at the Chico Mendes Institute of Biodiversity Conservation - CEPTA/ICMBio, Pirassununga, São Paulo, Brazil
| | - Alexandre Ninhaus-Silveira
- Pós-Graduação em Biologia Animal, Universidade Estadual Paulista "Júlio de Mesquita Filho", São José do Rio Preto, Brazil
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Murakami S, Hayashi T, Kinoshita M. Effects of salt or cosolvent addition on solubility of a hydrophobic solute in water: Relevance to those on thermal stability of a protein. J Chem Phys 2017; 146:055102. [DOI: 10.1063/1.4975165] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
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6
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Murakami S, Kinoshita M. Effects of monohydric alcohols and polyols on the thermal stability of a protein. J Chem Phys 2016; 144:125105. [PMID: 27036482 DOI: 10.1063/1.4944680] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The thermal stability of a protein is lowered by the addition of a monohydric alcohol, and this effect becomes larger as the size of hydrophobic group in an alcohol molecule increases. By contrast, it is enhanced by the addition of a polyol possessing two or more hydroxyl groups per molecule, and this effect becomes larger as the number of hydroxyl groups increases. Here, we show that all of these experimental observations can be reproduced even in a quantitative sense by rigid-body models focused on the entropic effect originating from the translational displacement of solvent molecules. The solvent is either pure water or water-cosolvent solution. Three monohydric alcohols and five polyols are considered as cosolvents. In the rigid-body models, a protein is a fused hard spheres accounting for the polyatomic structure in the atomic detail, and the solvent is formed by hard spheres or a binary mixture of hard spheres with different diameters. The effective diameter of cosolvent molecules and the packing fractions of water and cosolvent, which are crucially important parameters, are carefully estimated using the experimental data of properties such as the density of solid crystal of cosolvent, parameters in the pertinent cosolvent-cosolvent interaction potential, and density of water-cosolvent solution. We employ the morphometric approach combined with the integral equation theory, which is best suited to the physical interpretation of the calculation result. It is argued that the degree of solvent crowding in the bulk is the key factor. When it is made more serious by the cosolvent addition, the solvent-entropy gain upon protein folding is magnified, leading to the enhanced thermal stability. When it is made less serious, the opposite is true. The mechanism of the effects of monohydric alcohols and polyols is physically the same as that of sugars. However, when the rigid-body models are employed for the effect of urea, its addition is predicted to enhance the thermal stability, which conflicts with the experimental fact. We then propose, as two essential factors, not only the solvent-entropy gain but also the loss of protein-solvent interaction energy upon protein folding. The competition of changes in these two factors induced by the cosolvent addition determines the thermal-stability change.
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Affiliation(s)
- Shota Murakami
- Graduate School of Energy Science, Kyoto University, Uji, Kyoto 611-0011, Japan
| | - Masahiro Kinoshita
- Institute of Advanced Energy, Kyoto University, Uji, Kyoto 611-0011, Japan
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Abboud J, Storey KB. Novel control of lactate dehydrogenase from the freeze tolerant wood frog: role of posttranslational modifications. PeerJ 2013; 1:e12. [PMID: 23638346 PMCID: PMC3628601 DOI: 10.7717/peerj.12] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2012] [Accepted: 01/02/2013] [Indexed: 11/20/2022] Open
Abstract
Lactate dehydrogenase (LDH), the terminal enzyme of anaerobic glycolysis, plays a crucial role both in sustaining glycolytic ATP production under oxygen-limiting conditions and in facilitating the catabolism of accumulated lactate when stress conditions are relieved. In this study, the effects on LDH of in vivo freezing and dehydration stresses (both of which impose hypoxia/anoxia stress on tissues) were examined in skeletal muscle of the freeze-tolerant wood frog, Rana sylvatica. LDH from muscle of control, frozen and dehydrated wood frogs was purified to homogeneity in a two-step process. The kinetic properties and stability of purified LDH were analyzed, revealing no significant differences in V max, K m and I 50 values between control and frozen LDH. However, control and dehydrated LDH differed significantly in K m values for pyruvate, lactate, and NAD, I 50 urea, and in temperature, glucose, and urea effects on these parameters. The possibility that posttranslational modification of LDH was responsible for the stable differences in enzyme behavior between control and dehydrated states was assessed using ProQ diamond staining to detect phosphorylation and immunoblotting to detect acetylation, methylation, ubiquitination, SUMOylation and nitrosylation of the enzyme. LDH from muscle of dehydrated wood frogs showed significantly lower levels of acetylation, providing one of the first demonstrations of a potential role for protein acetylation in the stress-responsive control of a metabolic enzyme.
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Affiliation(s)
- Jean Abboud
- Institute of Biochemistry, Department of Biology and Department of Chemistry , Carleton University , Canada
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8
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Affiliation(s)
- C. J. Gray
- Department of Chemistry, University of Birmingham, PO Box 363, Birmingham, B15 2TT, England
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9
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Bonincontro A, Cinelli S, Onori G, Stravato A. Dielectric behavior of lysozyme and ferricytochrome-c in water/ethylene-glycol solutions. Biophys J 2004; 86:1118-23. [PMID: 14747346 PMCID: PMC1303904 DOI: 10.1016/s0006-3495(04)74186-7] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
This work deals with a dielectric study at radio frequencies of the influence at room temperature of two organic molecules, known as cryo-protectants, ethylene-glycol and glycerol, on conformational and dynamic properties of two model proteins, lysozyme (lys) from chicken egg-white and ferricytochrome-c (cyt-c) from horse heart. Cyt-c is a compact globular protein whereas lys is composed of two structural domains, separated by the active site cleft. Measurements were carried out at the fixed temperature of 20 degrees C varying the concentration of the cosolvent up to 90% w/w. From the analysis of the dielectric relaxation of the protein solution, the effective hydrodynamic radius and the electric dipole moment of the protein were calculated as a function of the cosolvent concentration. The data show that glycerol does not modify significantly the conformation of both proteins and cyt-c is also stable in the presence of ethylene-glycol. On the contrary ethylene-glycol strongly affects the dielectric response of lysozyme denoting a specific effect on its conformation and dynamics. The data are coherently interpreted hypothesizing that glycol molecule wedges between and separates the two domains of lys making them rotationally independent.
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Affiliation(s)
- A Bonincontro
- INFM-Dipartimento di Fisica, Università La Sapienza, I-00185 Rome, Italy.
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10
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Glycerol-Induced Aggregation of the Oligomeric L-Asparaginase II from E. coli Monitored with ATR-FTIR. Int J Mol Sci 2001. [DOI: 10.3390/i2020109] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
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11
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Gooding JJ, Erokhin P, Losic D, Yang W, Policarpio V, Liu J, Ho FM, Situmorang M, Hibbert DB, Shapter JG. Parameters important in fabricating enzyme electrodes using self-assembled monolayers of alkanethiols. ANAL SCI 2001; 17:3-9. [PMID: 11993674 DOI: 10.2116/analsci.17.3] [Citation(s) in RCA: 60] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
Abstract
The fabrication of enzyme electrodes using self-assembled monolayers (SAMs) has attracted considerable interest because of the spatial control over the enzyme immobilization. A model system of glucose oxidase covalently bound to a gold electrode modified with a SAM of 3-mercaptopropionic acid was investigated with regard to the effect of fabrication variables such as the surface topography of the underlying gold electrode, the conditions during covalent attachment of the enzyme and the buffer used. The resultant monolayer enzyme electrodes have excellent sensitivity and dynamic range which can easily be adjusted by controlling the amount of enzyme immobilized. The major drawback of such electrodes is the response which is limited by the kinetics of the enzyme rather than mass transport of substrates. Approaches to bringing such enzyme electrodes into the mass transport limiting regime by exploiting direct electron transfer between the enzyme and the electrode are outlined.
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Affiliation(s)
- J J Gooding
- School of Chemistry, The University of New South Wales, Sydney, Australia.
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12
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Tanner JW, Eckenhoff RG, Liebman PA. Halothane, an inhalational anesthetic agent, increases folding stability of serum albumin. BIOCHIMICA ET BIOPHYSICA ACTA 1999; 1430:46-56. [PMID: 10082932 DOI: 10.1016/s0167-4838(98)00258-1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Inhalational anesthetic agents are known to alter protein function, but the nature of the interactions underlying these effects remains poorly understood. We have used differential scanning calorimetry to study the effects of the anesthetic agent halothane on the thermally induced unfolding transition of bovine serum albumin. We find that halothane (0.6-10 mM) stabilizes the folded state of this protein, increasing its transition midpoint temperature from 62 to 71 degrees C. Binding of halothane to the native state of serum albumin thus outweighs any non-specific interactions between the thermally unfolded state of serum albumin and halothane in this concentration range. Based on the average enthalpy change DeltaH for unfolding of 170 kcal/mol, the increase from 62 to 71 degrees C corresponds to an additional Gibbs energy of stabilization (DeltaDeltaG) due to halothane of more than 4 kcal/mol. Analysis of the dependence of DeltaDeltaG on halothane concentration shows that thermal unfolding of a bovine serum albumin molecule is linked to the dissociation of about one halothane molecule at lower halothane concentrations and about six at higher halothane concentrations. Serum albumin is the first protein that has been shown to be stabilized by an inhalational anesthetic.
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Affiliation(s)
- J W Tanner
- Department of Anesthesia, University of Pennsylvania, 3400 Spruce Street, Philadelphia, PA 19104, USA.
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13
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Adaptations for Freezing Survival in Ectothermic Vertebrates. ACTA ACUST UNITED AC 1997. [DOI: 10.1016/s1569-2558(08)60073-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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14
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Raibekas AA, Massey V. Glycerol-induced development of catalytically active conformation of Crotalus adamanteus L-amino acid oxidase in vitro. Proc Natl Acad Sci U S A 1996; 93:7546-51. [PMID: 8755511 PMCID: PMC38782 DOI: 10.1073/pnas.93.15.7546] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023] Open
Abstract
The reconstitutable apoprotein of Crotalus adamanteus L-amino acid oxidase was prepared using hydrophobic interaction chromatography. After reconstitution with flavin adenine dinucleotide, the resulting protein was inactive, with a perturbed conformation of the flavin binding site. Subsequently, a series of cosolvent-dependent compact intermediates was identified. The nearly complete activation of the reconstituted apoprotein and the restoration of its native flavin binding site was achieved in the presence of 50% glycerol. We provide evidence that in addition to a merely stabilizing effect of glycerol on native proteins, glycerol can also have a restorative effect on their compact equilibrium intermediates, and we suggest the hydrophobic effect as a dominating force in this in vitro-assisted restorative process.
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Affiliation(s)
- A A Raibekas
- Department of Biological Chemistry, The University of Michigan Medical School, Ann Arbor 48109-0606, USA
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15
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Huang P, Dong A, Caughey WS. Effects of dimethyl sulfoxide, glycerol, and ethylene glycol on secondary structures of cytochrome c and lysozyme as observed by infrared spectroscopy. J Pharm Sci 1995; 84:387-92. [PMID: 7629725 DOI: 10.1002/jps.2600840402] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
Effects of 10-30% (v/v) of dimethyl sulfoxide, glycerol, and ethylene glycol on the H-O-H bending vibration of water and the amide I bands of horse heart cytochrome c and chicken egg white lysozyme in 25 mM sodium phosphate buffer (pH 7.4) were examined at 20 degrees C by Fourier transform infrared spectroscopy. The H-O-H bending mode of water was strongly affected by these cryoprotectant solvents. Increasing the concentration of cryosolvents from 0 to 30% shifts the water bending band maximum from 1645 to about 1650 cm-1. Second-derivative analysis reveals significant changes in conformation-sensitive amide I regions of lysozyme ascribed to alpha-helix (1657 cm-1), turn (1674 cm-1), and unordered (1646 cm-1) structures; each cryosolvent increases the intensity of the 1657 cm-1 band at the expense of bands at 1674 and 1646 cm-1. No changes in spectra deemed significant were observed for cytochrome c under the same conditions. There is no spectral evidence of structural randomization of proteins due to the presence of these cryosolvents. Cryosolvent-induced changes in secondary structure of proteins may result from changes in water structure which, in turn, perturb the structure of the protein and/or from direct interactions between cryosolvent and protein.
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Affiliation(s)
- P Huang
- Department of Biochemistry and Molecular Biology, Colorado State University, Fort Collins 80523, USA
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16
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Aliphatic alcohols stabilize an alternative conformation of the tryptophan synthase alpha 2 beta 2 complex from Salmonella typhimurium. J Biol Chem 1994. [DOI: 10.1016/s0021-9258(17)34032-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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17
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de Cordt S, Hendrickx M, Maesmans G, Tobback P. The influence of polyalcohols and carbohydrates on the thermostability of ?-amylase. Biotechnol Bioeng 1994; 43:107-14. [DOI: 10.1002/bit.260430202] [Citation(s) in RCA: 69] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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18
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Changing the Thermostability of Bacillus Licheniformis α-amylase. ACTA ACUST UNITED AC 1993. [DOI: 10.1016/b978-0-444-89372-7.50034-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register]
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19
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20
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Wang JM, Takeda A, Yang JT, Wu CS. Conformation of concanavalin A and its fragments in aqueous solution and organic solvent-water mixtures. JOURNAL OF PROTEIN CHEMISTRY 1992; 11:157-64. [PMID: 1388664 DOI: 10.1007/bf01025220] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The conformations of concanavalin A (con A), an all-beta protein, and its three CNBr-cleaved fragments were studied by CD. Con A in buffer showed a 197 nm maximum and a 223 nm minimum, which were red-shifted by 6-7 nm from those of regular all-beta proteins and beta-sheet of (Lys)n. Fragment 1 (residue 1-42) resembled an unordered form with a CD maximum at 200 nm, but fragments 2 (residues 43-129) and 3 (residues 130-237) showed a regular CD spectrum with two extrema at 192-193 nm (+) and 214-216 nm (-). Equimolar mixture of the three fragments showed some degree of interaction, but did not reconstitute the conformation of native con A, probably because of the loss of bound Ca2+ and Mn2+ ions in the fragments. In ethanol-, methanol-, and dioxane-water mixed solvents, con A and its fragments remained as beta-sheet. In contrast, addition of trifluoroethanol and sodium dodecyl sulfate induced alpha-helix at the expense of beta-sheet for con A and its fragments in aqueous solution. In 80% trifluoroethanol, the induced helicities exceeded their sequence-predicted helix-potentials, but in 10 mM sodium dodecyl sulfate the helicities agreed well with corresponding predictions.
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Affiliation(s)
- J M Wang
- Cardiovascular Research Institute, University of California, San Francisco
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22
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Storey KB, Keefe D, Kourtz L, Storey JM. Glucose-6-phosphate dehydrogenase in cold hardy insects: Kinetic properties, freezing stabilization, and control of hexose monophosphate shunt activity. ACTA ACUST UNITED AC 1991. [DOI: 10.1016/0020-1790(91)90046-h] [Citation(s) in RCA: 31] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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23
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Arakawa T, Carpenter JF, Kita YA, Crowe JH. The basis for toxicity of certain cryoprotectants: A hypothesis. Cryobiology 1990. [DOI: 10.1016/0011-2240(90)90017-x] [Citation(s) in RCA: 136] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
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24
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Nakano T, Fink AL. The folding of staphylococcal nuclease in the presence of methanol or guanidine thiocyanate. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)38354-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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25
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Swedberg SA, Pesek JJ, Fink AL. Attenuated total reflectance Fourier transform infrared analysis of an acyl-enzyme intermediate of alpha-chymotrypsin. Anal Biochem 1990; 186:153-8. [PMID: 2356965 DOI: 10.1016/0003-2697(90)90589-2] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Attenuated total reflectance Fourier transform infrared (FTIR) spectroscopy was used to obtain signal enhancement of the spectrum of the trans-cinnamoyl-alpha-chymotrypsin acyl-enzyme intermediate. Dilute solutions (as low as 2.5 mg/ml) of enzyme or stabilized acyl-enzyme intermediate were used to form thin films on a germanium crystal surface. The secondary structure of the enzyme thin film was shown to be consistent with the native secondary structure using deconvoluted FTIR data. A novel subtraction technique was used to eliminate interfering spectra of water vapor and protein in critical regions of analysis for esters. This permitted the difference spectra of the one new ester carbonyl bond to be discerned from the 300 or so amide bonds in the protein. The results suggest that the acyl-enzyme exists in two different conformations. This study demonstrates that ir structural information of enzyme-substrate or enzyme-inhibitor complexes can be obtained with dilute protein solutions.
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Affiliation(s)
- S A Swedberg
- Department of Chemistry, University of California, Santa Cruz 95064
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26
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Hatley RH, Franks F. The effect of aqueous methanol cryosolvents on the heat- and cold-induced denaturation of lactate dehydrogenase. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 184:237-40. [PMID: 2776766 DOI: 10.1111/j.1432-1033.1989.tb15012.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The effect on the low-temperature-induced denaturation temperature of various concentrations of methanol has been studied for lactate dehydrogenase. The results have been compared to similar data for the thermal denaturation temperature. Extrapolations of the low-temperature data show that, in a physiological buffer in the absence of methanol, the cold denaturation temperature would be -30 degrees C. Data obtained with high concentrations of methanol indicate that residues are exposed to a similar degree upon either heat- or cold-induced denaturation. Aggregation does not occur in the cold-denatured protein. Cold-induced denaturation is fully reversible at a protein concentration of 250 micrograms/ml. The spectra of the two denatured forms are similar.
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Affiliation(s)
- R H Hatley
- Pafra Ltd, Biopreservation Division, Cambridge, UK
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27
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Sinicropi DV, Hoke VB, McIlwain DL. Isolation of motoneuron cell bodies from spinal cord stored at -70 degrees C in ethylene glycol. Anal Biochem 1989; 180:286-90. [PMID: 2817357 DOI: 10.1016/0003-2697(89)90432-6] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Pretreatment of spinal cord with ethylene glycol permits long-term storage of the tissue at -70 degrees C prior to isolation and biochemical analysis of the cell bodies of spinal motoneurons. The method is useful for storing spinal tissue from laboratory animals, as well as from human post mortem specimens, where aliquots of tissue may then be used for motoneuron isolation over an indefinitely long period. In addition to inhibiting the loss of soluble proteins from the neurons during freezing and thawing, cryoprotection increases the yield and improves the appearance of the isolated cell bodies. The method should aid biochemical studies of many kinds of neuronal subpopulations isolated from small amounts of starting material.
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Affiliation(s)
- D V Sinicropi
- Department of Physiology, University of North Carolina School of Medicine, Chapel Hill 27514
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Storey KB, Storey JM. Freeze Tolerance and Freeze Avoidance in Ectotherms. ADVANCES IN COMPARATIVE AND ENVIRONMENTAL PHYSIOLOGY 1989. [DOI: 10.1007/978-3-642-74078-7_2] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
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Enzymatic reactions in aqueous—Organic media. v.1 Medium effect on the esterification of aromatic amino acids by α-chymotrypsin. Enzyme Microb Technol 1988. [DOI: 10.1016/0141-0229(88)90103-2] [Citation(s) in RCA: 34] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
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Abstract
We have tested the capacity of 28 different compounds to protect lactate dehydrogenase from damage during freeze-thawing. These solutes come from very dissimilar chemical classes including sugars, polyols, amino acids, methylamines, and lyotropic salts. All the compounds tested, except NaCl, protected the enzyme, to varying degrees, from inactivation. The only characteristic that these compounds have in common, as a group, is that they have all been shown to be preferentially excluded from contact with the surface of proteins in aqueous solution. It has been demonstrated previously (via thermodynamic arguments) that this interaction of solutes with proteins leads to the stabilization of proteins in nonfrozen, aqueous systems. Conversely, those solutes, e.g., urea and guanidine HCl, that bind to proteins destabilize proteins in solution, and we have found that they also enhanced the inactivation of lactate dehydrogenase during freeze-thawing. Based on the results of our freeze-thawing experiments and a review of the theory of protein stabilization in nonfrozen, aqueous solution we propose that the cryoprotection afforded to isolated proteins by solutes can be accounted for by the fact that these solutes are preferentially excluded from contact with the protein's surface.
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Affiliation(s)
- J F Carpenter
- Department of Zoology, University of California, Davis, 95616
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Fahy GM, Levy DI, Ali SE. Some emerging principles underlying the physical properties, biological actions, and utility of vitrification solutions. Cryobiology 1987; 24:196-213. [PMID: 3595164 DOI: 10.1016/0011-2240(87)90023-x] [Citation(s) in RCA: 135] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Vitrification solutions are aqueous cryoprotectant solutions which do not freeze when cooled at moderate rates to very low temperatures. Vitrification solutions have been used with great success for the cryopreservation of some biological systems but have been less successful or unsuccessful with other systems, and more fundamental knowledge about vitrification solutions is required. The purpose of the present survey is to show that a general understanding of the physical behavior and biological effects of vitrification solutions, as well as an understanding of the conditions under which vitrification solutions are required, is gradually emerging. Detailed nonequilibrium phase diagram information in combination with specific information on the tolerance of biological systems to ice and to cryoprotectant at subzero temperatures provides a quantitative theoretical basis for choosing between vitrification and freezing. The vitrification behavior of mixtures of cryoprotective agents during cooling is predictable from the behavior of the individual agents, and the behavior of individual agents is gradually becoming predictable from the details of their molecular structures. Progress is continuing concerning the elucidation of mechanisms and cellular sites of toxicity and mechanisms for the reduction of toxicity. Finally, important new information is rapidly emerging concerning the crystallization of previously vitrified cryoprotectant solutions during warming. It appears that vitrification tendency, toxicity, and devitrification all depend on subtle variations in the organization of water around dissolved substances.
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Fink AL, Painter B. Characterization of the unfolding of ribonuclease A in aqueous methanol solvents. Biochemistry 1987; 26:1665-71. [PMID: 3593684 DOI: 10.1021/bi00380a027] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
The effect of methanol on the thermal denaturation of ribonuclease A has been investigated over the -40 to 70 degrees C range. The transition was fully reversible to at least 60% (v/v) methanol at an apparent pH of cryosolvent (pH) of 3.0 and was examined at methanol concentrations as high as 80%. The unfolding transition, as monitored by absorbance change at 286 nm, became progressively broader and occurred at increasingly lower temperatures as the alcohol concentration increased. In 50% methanol, increasing the pH from 2 to 6 shifted the transition to higher temperature. A substantial decrease in cooperativity was noted at the more acidic conditions. On the other hand, increasing concentrations of guanidine hydrochloride in 50% methanol caused the transition to shift to lower temperatures with little effect on the cooperativity. The observed effects on the cooperativity of the unfolding transition suggest that methanol and lower temperatures may increase the concentration of partially folded intermediate states in the unfolding of ribonuclease. Comparison of the transition in 50% methanol as determined by absorbance or fluorescence, which monitor the degree of exposure of buried tyrosines and hence the tertiary structure, to that determined by far-UV circular dichroism, which monitors secondary structure, indicated that the major unfolding transition occurred at a higher temperature in the latter case. Thus, the tertiary structure is lost at a lower temperature than the secondary structure. This observation is consistent with a model of protein folding in which initially formed regions of secondary structure pack together, predominantly by hydrophobic interactions, to give the tertiary structure.(ABSTRACT TRUNCATED AT 250 WORDS)
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