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Starnes HM, Jackson TW, Rock KD, Belcher SM. Quantitative cross-species comparison of serum albumin binding of per- and polyfluoroalkyl substances from five structural classes. Toxicol Sci 2024; 199:132-149. [PMID: 38518100 PMCID: PMC11057469 DOI: 10.1093/toxsci/kfae028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/24/2024] Open
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a class of over 8000 chemicals, many of which are persistent, bioaccumulative, and toxic to humans, livestock, and wildlife. Serum protein binding affinity is instrumental in understanding PFAS toxicity, yet experimental binding data is limited to only a few PFAS congeners. Previously, we demonstrated the usefulness of a high-throughput, in vitro differential scanning fluorimetry assay for determination of relative binding affinities of human serum albumin for 24 PFAS congeners from 6 chemical classes. In the current study, we used this assay to comparatively examine differences in human, bovine, porcine, and rat serum albumin binding of 8 structurally informative PFAS congeners from 5 chemical classes. With the exception of the fluorotelomer alcohol 1H, 1H, 2H, 2H-perfluorooctanol (6:2 FTOH), each PFAS congener bound by human serum albumin was also bound by bovine, porcine, and rat serum albumin. The critical role of the charged functional headgroup in albumin binding was supported by the inability of albumin of each species tested to bind 6:2 FTOH. Significant interspecies differences in serum albumin binding affinities were identified for each of the bound PFAS congeners. Relative to human albumin, perfluoroalkyl carboxylic and sulfonic acids were bound with greater affinity by porcine and rat serum albumin, and the perfluoroalkyl ether acid congener bound with lower affinity to porcine and bovine serum albumin. These comparative affinity data for PFAS binding by serum albumin from human, experimental model, and livestock species reduce critical interspecies uncertainty and improve accuracy of predictive bioaccumulation and toxicity assessments for PFAS.
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Affiliation(s)
- Hannah M Starnes
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27607, USA
| | - Thomas W Jackson
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27607, USA
| | - Kylie D Rock
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27607, USA
| | - Scott M Belcher
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina 27607, USA
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Starnes HM, Jackson TW, Rock KD, Belcher SM. Quantitative Cross-Species Comparison of Serum Albumin Binding of Per- and Polyfluoroalkyl Substances from Five Structural Classes. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.10.566613. [PMID: 38014292 PMCID: PMC10680784 DOI: 10.1101/2023.11.10.566613] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Per- and polyfluoroalkyl substances (PFAS) are a class of over 8,000 chemicals that are persistent, bioaccumulative, and toxic to humans, livestock, and wildlife. Serum protein binding affinity is instrumental in understanding PFAS toxicity, yet experimental binding data is limited to only a few PFAS congeners. Previously, we demonstrated the usefulness of a high-throughput, in vitro differential scanning fluorimetry assay for determination of relative binding affinities of human serum albumin for 24 PFAS congeners from 6 chemical classes. In the current study, we used this differential scanning fluorimetry assay to comparatively examine differences in human, bovine, porcine, and rat serum albumin binding of 8 structurally informative PFAS congeners from 5 chemical classes. With the exception of the fluorotelomer alcohol 1H,1H,2H,2H-perfluorooctanol (6:2 FTOH), each PFAS congener bound by human serum albumin was also bound by bovine, porcine, and rat serum albumin. The critical role of the charged functional headgroup in albumin binding was supported by the inability of serum albumin of each species tested to bind 6:2 FTOH. Significant interspecies differences in serum albumin binding affinities were identified for each of the bound PFAS congeners. Relative to human albumin, perfluoroalkyl carboxylic and sulfonic acids were bound with greater affinity by porcine and rat serum albumin, and perfluoroalkyl ether congeners bound with lower affinity to porcine and bovine serum albumin. These comparative affinity data for PFAS binding by serum albumin from human, experimental model and livestock species reduce critical interspecies uncertainty and improve accuracy of predictive toxicity assessments for PFAS.
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Affiliation(s)
- Hannah M. Starnes
- Department of Biological Sciences, North Carolina State University, 127 David Clark Labs Campus Box 7617, Raleigh, NC 27607, USA
| | - Thomas W. Jackson
- Department of Biological Sciences, North Carolina State University, 127 David Clark Labs Campus Box 7617, Raleigh, NC 27607, USA
- Current address: Public Health and Integrated Toxicology Division, Center for Public Health and Environmental Assessment, U.S. Environmental Protection Agency, Research Triangle Park, NC 27711, USA
| | - Kylie D. Rock
- Department of Biological Sciences, North Carolina State University, 127 David Clark Labs Campus Box 7617, Raleigh, NC 27607, USA
- Current address: Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
| | - Scott M. Belcher
- Department of Biological Sciences, North Carolina State University, 127 David Clark Labs Campus Box 7617, Raleigh, NC 27607, USA
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Nemergut M, Sedláková D, Fabriciová G, Belej D, Jancura D, Sedlák E. Explanation of inconsistencies in the determination of human serum albumin thermal stability. Int J Biol Macromol 2023; 232:123379. [PMID: 36702231 DOI: 10.1016/j.ijbiomac.2023.123379] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2022] [Revised: 01/15/2023] [Accepted: 01/18/2023] [Indexed: 01/24/2023]
Abstract
Thermal denaturation of human serum albumin has been the subject of many studies in recent decades, but the results of these studies are often conflicting and inconclusive. To clarify this, we combined different spectroscopic and calorimetric techniques and performed an in-depth analysis of the structural changes that occur during the thermal unfolding of different conformational forms of human serum albumin. Our results showed that the inconsistency of the results in the literature is related to the different quality of samples in different batches, methodological approaches and experimental conditions used in the studies. We confirmed that the presence of fatty acids (FAs) causes a more complex process of the thermal denaturation of human serum albumin. While the unfolding pathway of human serum albumin without FAs can be described by a two-step model, consisting of subsequent reversible and irreversible transitions, the thermal denaturation of human serum albumin with FAs appears to be a three-step process, consisting of a reversible step followed by two consecutive irreversible transitions.
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Affiliation(s)
- Michal Nemergut
- Center for Interdisciplinary Biosciences, P. J. Šafárik University in Košice, Jesenná 5, 04154 Košice, Slovakia
| | - Dagmar Sedláková
- Department of Biophysics, Institute of Experimental Physics, Slovak Academy of Sciences, Watsonova 47, 04001 Košice, Slovakia
| | - Gabriela Fabriciová
- Department of Biophysics, Faculty of Science, P. J. Šafárik University in Košice, Jesenná 5, 04154 Košice, Slovakia
| | - Dominik Belej
- Department of Biophysics, Faculty of Science, P. J. Šafárik University in Košice, Jesenná 5, 04154 Košice, Slovakia
| | - Daniel Jancura
- Department of Biophysics, Faculty of Science, P. J. Šafárik University in Košice, Jesenná 5, 04154 Košice, Slovakia
| | - Erik Sedlák
- Center for Interdisciplinary Biosciences, P. J. Šafárik University in Košice, Jesenná 5, 04154 Košice, Slovakia; Department of Biochemistry, Faculty of Science, P. J. Šafárik University in Košice, Moyzesova 11, 04154 Košice, Slovakia.
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4
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Akbarzadehlaleh P, Kamani A, Shamsasenjan K. An efficient non-chromatographic method to separate human serum albumin from cryo-poor plasma. SEP SCI TECHNOL 2022. [DOI: 10.1080/01496395.2022.2060837] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
Affiliation(s)
- Parvin Akbarzadehlaleh
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Abubakr Kamani
- Department of Pharmaceutical Biotechnology, Faculty of Pharmacy, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Karim Shamsasenjan
- Department of Immunology, Faculty of Medicine, Tabriz University of Medical Sciences, Tabriz, Iran
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Alsabeeh N, Chausse B, Kakimoto PA, Kowaltowski AJ, Shirihai O. Cell culture models of fatty acid overload: Problems and solutions. Biochim Biophys Acta Mol Cell Biol Lipids 2017; 1863:143-151. [PMID: 29155055 DOI: 10.1016/j.bbalip.2017.11.006] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2017] [Revised: 11/09/2017] [Accepted: 11/14/2017] [Indexed: 12/17/2022]
Abstract
High plasma levels of fatty acids occur in a variety of metabolic diseases. Cellular effects of fatty acid overload resulting in negative cellular responses (lipotoxicity) are often studied in vitro, in an attempt to understand mechanisms involved in these diseases. Fatty acids are poorly soluble, and thus usually studied when complexed to albumins such as bovine serum albumin (BSA). The conjugation of fatty acids to albumin requires care pertaining to preparation of the solutions, effective free fatty acid concentrations, use of different fatty acid species, types of BSA, appropriate controls and ensuring cellular fatty acid uptake. This review discusses lipotoxicity models, the potential problems encountered when using these cellular models, as well as practical solutions for difficulties encountered.
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Affiliation(s)
- Nour Alsabeeh
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA; Department of Physiology and Biophysics, Boston University School of Medicine, Boston, MA 02118, USA; Department of Physiology, Faculty of Medicine, Kuwait University, Kuwait
| | - Bruno Chausse
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil
| | - Pamela A Kakimoto
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil
| | - Alicia J Kowaltowski
- Departamento de Bioquímica, Instituto de Química, Universidade de São Paulo, São Paulo, SP 05508-000, Brazil.
| | - Orian Shirihai
- Department of Medicine, Division of Endocrinology, Diabetes and Hypertension, UCLA David Geffen School of Medicine, Los Angeles, CA 90095, USA
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6
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Molodenskii DS. VecDec4SAS program for analyzing the dynamic processes observed by the small-angle scattering technique. CRYSTALLOGR REP+ 2017. [DOI: 10.1134/s1063774517010114] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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7
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Bleustein CB, Sennett M, Kung RT, Felsen D, Poppas DP, Stewart RB. Differential scanning calorimetry of albumin solders: interspecies differences and fatty acid binding effects on protein denaturation. Lasers Surg Med 2001; 27:465-70. [PMID: 11126440 DOI: 10.1002/1096-9101(2000)27:5<465::aid-lsm1007>3.0.co;2-s] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND AND OBJECTIVE Understanding albumin solder denaturation is important for laser tissue soldering. Human (HSA), bovine (BSA), porcine (PSA), and canine (CSA) albumin both fatty acid containing (FAC) and fatty acid free (FAF) were evaluated by using differential scanning calorimetry (DSC). STUDY DESIGN/MATERIALS AND METHODS DSC was used to measure difference thermograms to determine the irreversible thermal denaturation profile for 50% albumin solutions. The denaturation transition's onset, end and peak temperatures, and enthalpy were measured. RESULTS All FAC species, except BSA, exhibited twin peaked endotherms. Single endotherms were observed for all FAF species and BSA-FAC. Onset and end temperatures were significantly [P < 0.001] lower for all FAF species (except BSA's end temperature). There was a 30% decrease in the denaturation enthalpy between FAF and FAC groups. CONCLUSION FAF albumin solders were found to denature at significantly lower temperatures, while also having a 30% reduction in enthalpy when compared with their FAC counterparts.
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Affiliation(s)
- C B Bleustein
- Center for Pediatric Urology, Department of Urology, New York Presbyterian Hospital-Weill Medical College of Cornell University, New York 10021, USA
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Abstract
'Condensation diseases' are heterogeneous pathological conditions in which the primary pathogenetic step is the loss of solubility of specific substances, resulting in the formation of a condensed phase. Typical examples are cataract, nephrolithiasis, gallstone disease and certain rheumatic conditions in which protein denaturation, aggregation and precipitation may occur. Since the condensing molecules are often proteins, antidenaturant agents should be considered rational drugs for the treatment of these diseases. Surprisingly, however, only a few molecules with these properties are currently available for therapeutic use, including bendazac for cataract.
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Affiliation(s)
- L Saso
- Department of Pharmacology of Natural Substances and General Physiology, University of Rome "La Sapienza", Rome, Italy
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Carpenter JF, Kendrick BS, Chang BS, Manning MC, Randolph TW. Inhibition of stress-induced aggregation of protein therapeutics. Methods Enzymol 1999; 309:236-55. [PMID: 10507028 DOI: 10.1016/s0076-6879(99)09018-7] [Citation(s) in RCA: 105] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Affiliation(s)
- J F Carpenter
- Department of Pharmaceutical Sciences, University of Colorado Health Sciences Center, Denver 80262, USA
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Saso L, Valentini G, Mattei E, Panzironi C, Casini ML, Grippa E, Silvestrini B. Stabilization of rat serum proteins following oral administration of fish oil. Arch Pharm Res 1999; 22:485-90. [PMID: 10549576 DOI: 10.1007/bf02979157] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The mechanism of action of fish oil (FO), currently used in different chronic inflammatory conditions such as rheumatoid arthritis (RA), is not completely understood, although it is thought that it could alter the metabolism of endogenous autacoids. In addition, we hypothesized that the known capability of fatty acids (FA) of stabilizing serum albumin and perhaps other proteins, may be of pharmacological relevance considering that it is shared by other anti-rheumatic agents (e.g. nonsteroidal antiinflammatory drugs). Thus, we studied the effect of oral administration of FO and corn oil (CO), a vegetable oil with a different composition, on the stability of rat serum proteins, evaluated by a classical in vitro method based on heat-induced protein denaturation. FO, and, to a lower extent, CO inhibited heat-induced denaturation of rat serum (RS): based on the inhibitory activity (EC50) of the major fatty acids against heat-induced denaturation of RS in vitro, it was possible to speculate that in vivo effects of palmitic acid (C16:0) and eicosapentaenoic acid (EPA, C20:5, n-3) may be more relevant than that of linolenic acid (C18:2). To better investigate this phenomenon, we extracted albumin from the serum of animals treated or not with FO with a one-step affinity chromatography technique, obtaining high purity rat serum albumin preparations (RSA-CTRL and RSA-FO), as judged by SDS-PAGE with Coomassie blue staining. When these RSA preparations were heated at 70 degrees C for 30 min, it was noted that RSA-FO was much more stable than RSA-CTRL, presumably due to higher number of long chain fatty acids (FA) such as palmitic acid or EPA. In conclusion, we provided evidences that oral administration of FO in the rat stabilizes serum albumin, due to an increase in the number of protein bound long chain fatty acids (e.g. palmitic acid and EPA). We speculate that the stabilization of serum albumin and perhaps other proteins could prevent changes of antigenicity due to protein denaturation and glycosylation, which may trigger pathological autoimmune responses, suggesting that this action may be involved in the mode of action of FO in RA and other chronic inflammatory diseases.
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Affiliation(s)
- L Saso
- Department of Pharmacology of Natural Substances and General Physiology, University of Rome La Sapienza, Italy
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11
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Cerini C, Geider S, Dussol B, Hennequin C, Daudon M, Veesler S, Nitsche S, Boistelle R, Berthézène P, Dupuy P, Vazi A, Berland Y, Dagorn JC, Verdier JM. Nucleation of calcium oxalate crystals by albumin: involvement in the prevention of stone formation. Kidney Int 1999; 55:1776-86. [PMID: 10231440 DOI: 10.1046/j.1523-1755.1999.00426.x] [Citation(s) in RCA: 57] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND Urine is supersaturated in calcium oxalate, which means that it will contain calcium oxalate crystals that form spontaneously. Their size must be controlled to prevent retention in ducts and the eventual development of a lithiasis. This is achieved, in part, by specific inhibitors of crystal growth. We investigated whether promoters of crystal nucleation could also participate in that control, because for the same amount of salt that will precipitate from a supersaturated solution, increasing the number of crystals will decrease their average size and facilitate their elimination. METHODS Albumin was purified from commercial sources and from the urine of healthy subjects or idiopathic calcium stone formers. Its aggregation properties were characterized by biophysical and biochemical techniques. Albumin was then either attached to several supports or left free in solution and incubated in a metastable solution of calcium oxalate. Kinetics of calcium oxalate crystallization were determined by turbidimetry. The nature and efficiency of nucleation were measured by examining the type and number of neoformed crystals. RESULTS Albumin, one of the most abundant proteins in urine, was a powerful nucleator of calcium oxalate crystals in vitro, with the polymers being more active than monomers. In addition, nucleation by albumin apparently led exclusively to the formation of calcium oxalate dihydrate crystals, whereas calcium oxalate monohydrate crystals were formed in the absence of albumin. An analysis of calcium oxalate crystals in urine showed that the dihydrate form was present in healthy subjects and stone formers, whereas the monohydrate, which is thermodynamically more stable and constitutes the core of most calcium oxalate stones, was present in stone formers only. Finally, urinary albumin purified from healthy subjects contained significantly more polymers and was a stronger promoter of calcium oxalate nucleation than albumin from idiopathic calcium stone formers. CONCLUSIONS Promotion by albumin of calcium oxalate crystallization with specific formation of the dihydrate form might be protective, because with rapid nucleation of small crystals, the saturation levels fall; thus, larger crystal formation and aggregation with subsequent stone formation may be prevented. We believe that albumin may be an important factor of urine stability.
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Affiliation(s)
- C Cerini
- INSERM U315, Physiologie et Pathologie Digestives, Hôpital Sainte-Marguerite, Marseille, France
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12
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Sontum PC, Christiansen C. Photon correlation spectroscopy applied to characterisation of denaturation and thermal stability of human albumin. J Pharm Biomed Anal 1997; 16:295-302. [PMID: 9408847 DOI: 10.1016/s0731-7085(97)00032-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Photon correlation spectroscopy and light absorption measurements have been applied for characterisation of denaturation kinetics and thermal stability of human albumin in solution. The hydrodynamic size of the molecules has been studied as a function of pH, and the denaturation rate of ten different lots of 5% (w/v) human albumin solution has been measured at various temperatures. In the native (pH 7) state, the hydrodynamic molecular diameter was found to 6.3 nm. The molecular size was relatively stable between pH 10 and 5, but increased with decreasing pH to approximately 20 nm at pH 3. The denaturation rate, measured as change in hydrodynamic diameter per min, was strongly dependent on temperature and increased 3-fold per degree in the 73-75 degrees C range. The investigated lots of albumin solution showed large variations in stability at 74 degrees C, with denaturation rates ranging from 10 to 100 nm min-1. The observed thermal stability for the lots investigated was ranked identically with both the employed techniques. In an effort to explain the observed lot to lot variations in denaturation rate, a broad chemical characterisation including determination of free SH content, fatty acid content and composition and metal content, was performed. However, lot to lot variations in these parameters was not found to fully elucidate the observed variations in thermal stability.
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Affiliation(s)
- P C Sontum
- Research and Development Section, Nycomed Imaging AS, Oslo, Norway
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13
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Chiou JS, Ueda I. Ethanol unfolds firefly luciferase while competitive inhibitors antagonize unfolding: DSC and FTIR analyses. J Pharm Biomed Anal 1994; 12:969-75. [PMID: 7819382 DOI: 10.1016/0731-7085(94)00045-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Firefly luciferase has gained popularity as a protein model in elucidating anaesthesia mechanism because the bioluminescence of the purified enzyme system is extremely sensitive to volatile anaesthetics. This study analysed the thermal unfolding of firefly luciferase by differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR). DSC showed that the transition of firefly luciferase from the folded (N) to unfolded (D) state occurred at 41.7 degrees C with the excess heat flow of 1.6 cal g-1 protein. Ethanol decreased the transition temperature dose dependently. In contrast, luciferin competitors, anilinonaphthalenesulphonate (ANS), toluidinonaphthalenesulphonate (TNS), and myristic acid increased the transition temperature. The competitive inhibitors antagonized unfolding and stabilized the N-state. Ethanol promoted unfolding and stabilized the D-state. Temperature scan by FTIR agreed with the DSC data. The intensities of amide-I' and amide-II' bands started to increase at 20-25 degrees C. This temperature coincides with the temperature where the bioluminescence of firefly luciferase is maximal. The unfolding effect of ethanol was evident even at 5 degrees C. ANS, TNS, and myristic acid completely protected the enzyme from the thermal unfolding. This is the first demonstration that the noncompetitive inhibitors induce the isothermal first-order phase transition in a functional protein, whereas competitive inhibitors protect the enzyme from thermal unfolding. The action mode of competitive inhibitors on firefly luciferase is completely different from that of noncompetitive inhibitors.
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Affiliation(s)
- J S Chiou
- Department of Anesthesia, DVA Medical Center, Salt Lake City, UT 84148
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SMITH JL, YADA R. LIPOPHILIZATION OF MUCOR MIEHEI ASPARTYL PROTEINASE: EFFECT ON STRUCTURE-FUNCTION AND STABILITY. J Food Biochem 1991. [DOI: 10.1111/j.1745-4514.1991.tb00419.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
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15
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Ross PD, Shrake A. Decrease in stability of human albumin with increase in protein concentration. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37941-9] [Citation(s) in RCA: 53] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
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17
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Aoki K, Nagai I, Hiramatsu K. Behaviour of radioactive palmitic acid during heat treatment of bovine serum albumin. Int J Biol Macromol 1984. [DOI: 10.1016/0141-8130(84)90011-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
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18
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Shrake A, Finlayson JS, Ross PD. Thermal stability of human albumin measured by differential scanning calorimetry. I. Effects of caprylate and N-acetyltryptophanate. Vox Sang 1984; 47:7-18. [PMID: 6741034 DOI: 10.1111/j.1423-0410.1984.tb01556.x] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
The thermal stability of 5% previously unheated, undefatted human albumin monomer in 145 mM Na+, pH 7.0 was investigated by differential scanning calorimetry (DSC) as a function of added caprylate and/or N-acetyl-DL-tryptophanate. Caprylate was substantially more effective than N-acetyl-DL-tryptophanate in protecting the protein against thermal denaturation at a given level or at a saturating level of stabilizer. The tracing of the differential heat capacity versus temperature (thermogram) for this undefatted monomer that contained 1.5 mol endogenous, long-chain fatty acid (LCFA)/mol monomer exhibits two denaturation peaks (endotherms) in the absence of stabilizer. The endotherm with the lower denaturation temperature (Td) comprises 70% of the total heat of denaturation and also corresponds to irreversible denaturation and precipitation of 70% of the albumin. This endotherm is associated with more thermally labile protein species containing low levels of LCFA. The endotherm with the higher Td is associated with more stable protein species containing high levels of LCFA. Thus, the two endotherms are not related to the proposed domain structure of the protein but result from an uneven LCFA distribution that is due to preexisting heterogeneity in the albumin and/or heterogeneity that arises during the DSC experiment. Binding data do not support a preexisting uneven distribution of sufficient magnitude to explain the experimental results. A complementary explanation is that an uneven fatty acid distribution arises during the DSC experiment by migration of LCFA from the more labile species to the more stable as the former unfold; such migration would cause further stabilization of the latter.
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Abstract
The thermal stabilization of human albumin by caprylate (CA) and acetyltryptophanate (AT) was studied by monitoring the formation of albumin polymer (defined as species larger than dimer) on the basis of its molecular size as well as its characteristic migration as alpha-globulin. Heating 5% protein solutions of purified albumin monomer, cohn fraction V, and fraction IV-4 + V at 60 degrees C in 0.1 M sodium phosphate or 145 mM sodium chloride, pH 7.0, established the following order of stabilizer effectiveness: 4 mM CA + 4 mM AT approximately 4 mM CA greater than 8 mM AT greater than or equal to 2 mM CA greater than 4 mM AT. However, albumin was more thermally stable in the chloride medium. Raising the CA concentration above 4 mM provided little additional stabilization. The D- and L-enantiomers of AT were equally effective, but 16 mM AT was needed to equal the effect of 4 mM CA. L-Tryptophanate exerted only slight stabilization, even at 32 mM; D-tryptophanate was even less effective. The albumin polymer level increased progressively with time at 60 degrees C in 2 mM CA or 4 mM AT, whereas in 4 mM CA it reached a plateau in 4-6 h. Acetone drying of albumin-rich fractions was shown to remove nearly all endogenous fatty acid, rendering the protein thermally labile unless sufficient exogenous stabilizer(s) was added. Even in the presence of 145 mM sodium chloride and 4 mM CA + 4 mM AT or 4 mM CA, the stabilizing effect of endogenous fatty acid was still detectable.
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Aoki K, Hayakawa N, Noda K, Terada H, Hiramatsu K. Behavior of fatty acid during the incubation of bovine serum albumin. Entity of the serum albumin resistant to heat. Colloid Polym Sci 1983. [DOI: 10.1007/bf01413943] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
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Action of glycerol and sodium molybdate in stabilization of the progesterone receptor from rat trophoblast. J Biol Chem 1983. [DOI: 10.1016/s0021-9258(18)32525-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
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22
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Kim DH, Hahn Y, Hong SK. Stabilization of β-D-galactosidase from heat and chemical inactivation with the extract ofPanax ginseng C.A. Meyer. Arch Pharm Res 1982. [DOI: 10.1007/bf02856407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
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Terada H, Hiramatsu K, Aoki K. Heat denaturation of serum albumin monitored by 1-anilino-naphthalene-8-sulfonate. BIOCHIMICA ET BIOPHYSICA ACTA 1980; 622:161-70. [PMID: 7378445 DOI: 10.1016/0005-2795(80)90027-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
The process of heat denaturation of serum albumin, and the properties of several denatured components of albumin were studied using 1-anilino-naphthalene-8-sulfonate as a probe dye. Like native albumin, these protein species all induce fluorescence of the dye with maximum emission at 470 nm when excited at 380 nm. However, the affinity of albumin for the dye decreased on denaturation. This fluorescent dye bound competitively to both native and denatured albumin with another probe dye, 2-(4'-hydroxyphenylazo)benzoic acid, has a specific absorption band at about 480 nm on binding with native albumin. Fatty acids, such as lauric acid, inhibited the interaction of 1-anilinonaphthalene-8-sulfonate with native albumin, but had little effect on its binding with denatured albumin.
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Wetzel R, Becker M, Behlke J, Billwitz H, Böhm S, Ebert B, Hamann H, Krumbiegel J, Lassmann G. Temperature behaviour of human serum albumin. EUROPEAN JOURNAL OF BIOCHEMISTRY 1980; 104:469-78. [PMID: 6244951 DOI: 10.1111/j.1432-1033.1980.tb04449.x] [Citation(s) in RCA: 183] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Structural alterations of albumin, their dependence on concentration and the role of free --SH groups at thermal denaturation, as well as the reversibility of thermally induced structural changes, were studied. Application of various physical methods provides information on a series of structural parameters in a major concentration range. Apart from changes of the helix content, heat treatment gives rise to beta structures which are amplified on cooling and which are correlated with the aggregation of albumin. With rising temperature and concentration the proportion of beta structures and aggregates increases. At degrees of denaturation of up to 20% complete renaturation is possibly in every case. The structure content is concentration-dependent even at room temperature. It may be that intermolecular interactions induce additional alpha-helix structures which are less stable, however, than the ones stabilized by intramolecular interactions. Unfolding of the pocket containing the free --SH group of cysteine-34 enables disulphide bridges to be formed leading to stable aggregates and irreversible structural alterations. Through binding of N-ethymaleimide to free --SH groups, which blocks the formation of disulphide bridges, it is possible to prevent aggregation and irreversible conformational changes. At temperatures below 65--70 degrees C, oligomers are formed mainly via intermolecular beta structures.
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25
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Effect of citraconylation on the thermal aggregation of human serum albumin. Int J Biol Macromol 1980. [DOI: 10.1016/0141-8130(80)90002-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
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26
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Gumpen S, Hegg PO, Martens H. Thermal stability of fatty acid-serum albumin complexes studied by differential scanning calorimetry. BIOCHIMICA ET BIOPHYSICA ACTA 1979; 574:189-96. [PMID: 486509 DOI: 10.1016/0005-2760(79)90001-8] [Citation(s) in RCA: 85] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Differential scanning calorimetry has been used to study the thermal stability of bovine serum albumin as affected by binding of fatty acids (lauric acid and stearic acid) and sodium dodecyl sulfate (SDS). All the ligands stabilized the protein molecules in a similar manner, but to different levels. A maximum increase in denaturation temperature of 30 degrees C was obtained with lauric acid. The thermograms indicate the presence of several ligand-albumin complexes having different heat stabilities. Variations in pH in 0.9% NaCl affected the heat stability of both ligand-poor and ligand-rich albumin, the former being more sensitive to variations in pH within the physiological range. Variations in NaCl concentration affected the thermal stabilities at neutral pH, expecially at low salt concentrations. While ligand-rich albumin was somewhat destabilized by increasing NaCl concentrations, ligand-poor albumin was strongly stabilized. The potential use of differential scanning calorimetry in ligand-albumin research is discussed.
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Sjödin T. Circular dichroism studies on the inhibiting effect of oleic acid on the binding of diazepam to human serum albumin. Biochem Pharmacol 1977; 26:2157-61. [PMID: 588298 DOI: 10.1016/0006-2952(77)90268-4] [Citation(s) in RCA: 23] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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