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Wingfield PT, Palmer I, Liang SM. Folding and Purification of Insoluble (Inclusion Body) Proteins from Escherichia coli. CURRENT PROTOCOLS IN PROTEIN SCIENCE 2014; 78:6.5.1-6.5.30. [PMID: 25367010 DOI: 10.1002/0471140864.ps0605s78] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Heterologous expression of recombinant proteins in E. coli often results in the formation of insoluble and inactive protein aggregates, commonly referred to as inclusion bodies. To obtain the native (i.e., correctly folded) and hence active form of the protein from such aggregates, four steps are usually followed: (1) the cells are lysed, (2) the cell wall and outer membrane components are removed, (3) the aggregates are solubilized (or extracted) with strong protein denaturants, and (4) the solubilized, denatured proteins are folded with concomitant oxidation of reduced cysteine residues into the correct disulfide bonds to obtain the native protein. This unit features three different approaches to the final step of protein folding and purification. In the first, guanidine·HCl is used as the denaturant, after which the solubilized protein is folded (before purification) in an "oxido-shuffling" buffer system to increase the rate of protein oxidation. In the second, acetic acid is used to solubilize the protein, which is then partially purified by gel filtration before folding; the protein is then folded and oxidized by simple dialysis against water. Thirdly, folding and purification of a fusion protein using metal-chelate affinity chromatography are described.
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Affiliation(s)
| | - Ira Palmer
- Protein Expression Laboratory, NIAMD/NIH, Bethesda, Maryland
| | - Shu-Mei Liang
- Agricultural Biotechnology Research Center, Academia Sinica, Taipei, Taiwan
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2
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Cauchy M, Hefford MA. Excipient exchange in the comparison of preparations of the same biologic made by different manufacturing processes: An exploratory study with recombinant human growth hormone (rhGH). Biologicals 2010; 38:637-43. [DOI: 10.1016/j.biologicals.2010.07.005] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2010] [Revised: 07/16/2010] [Accepted: 07/22/2010] [Indexed: 10/19/2022] Open
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Vedantham G, Carothers SL, Belfort G, Przybycien TM. Structural Response of Bovine Growth Hormone to Dead-Ended Ultrafiltration. SEP SCI TECHNOL 2003. [DOI: 10.1081/ss-120016574] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
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Wingfield PT, Palmer I, Liang S. Folding and Purification of Insoluble (Inclusion Body) Proteins fromEscherichia coli. ACTA ACUST UNITED AC 2001; Chapter 6:Unit 6.5. [PMID: 18429192 DOI: 10.1002/0471140864.ps0605s00] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
| | - Ira Palmer
- National Institutes of Health Bethesda Maryland
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5
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Thamann TJ. A vibrational spectroscopic assignment of the disulfide bridges in recombinant bovine growth hormone and growth hormone analogs. SPECTROCHIMICA ACTA. PART A, MOLECULAR AND BIOMOLECULAR SPECTROSCOPY 1999; 55A:1661-1666. [PMID: 10439513 DOI: 10.1016/s1386-1425(98)00322-9] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/23/2023]
Abstract
Disulfide stretching vibrations for bovine growth hormone (bGH) occur in a vibrational envelope centered at 540 cm-1 which spans 480-580 cm-1. A multitude of vibrational bands present in this envelope, that are not related to disulfide stretching, emphasize the need for model compounds when assigning S-S stretching modes. Raman spectroscopic data for bGH analogs, in which one or both of the two disulfide bridges have been selectively cleaved, have been used to characterize the S-S stretching envelope for the two cystine links in bGH. The Raman data for the r-bGH analogs indicate that the number of disulfide bonds present in r-bGH is determined, not by the observance of the presence or absence of a single spectral peak, but by the relative intensity of vibrational envelope from 520-560 cm-1. Cleavage of disulfide bridges in bGH results in a general decrease in vibrational spectral intensity in the 520-560 cm-1 range. This decrease in intensity is proportional to the number of cystine links severed.
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6
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Thamann TJ. Raman spectroscopic studies of a dimeric form of recombinant bovine growth hormone. Anal Biochem 1998; 265:202-7. [PMID: 9882393 DOI: 10.1006/abio.1998.2879] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Lyophilized dimeric recombinant bovine growth hormone (r-bGH) produced through incubation of r-bGH at 37 degrees C and 96% relative humidity for 8 days was examined by Raman spectroscopy. The secondary structure of the dimeric material is comparable to that of nonincubated r-bGH, due to the high similarity of the amide I, III, and V vibrational envelopes of the two samples. The dimeric material exhibits disulfide stretching that is indicative of the presence of only one disulfide bond (Cys53-Cys164). No sulfhydryl S-H stretching vibrations are observed, suggesting that cysteines from the cleaved disulfide bridge (Cys181-Cys189) are bound to nonsulfur atoms. Either high humidity (96%) or mild heat (37 degrees C) alone will cleave only one disulfide bond, but the final products are different. Incubation at ambient temperature and high humidity leads to a significant secondary structural change, while mild heat at very low humidity does not alter r-bGH secondary structure. Spectral data for incubations solely in mild heat are consistent with r-bGH structures that have lost the small loop (Cys181-Cys189) disulfide bridge, while incubations under only high humidity conditions are compatible with what would be expected if the large loop (Cys53-Cys164) cystine link was broken. Mild heat and high humidity are both present in dimer formation, yet only the small loop bridge is severed. The data suggest that heat may be the primary factor in determining which cystine link is broken. More severe heating (75 degrees C) cleaves both cystines and alters both secondary and tertiary structure.
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Affiliation(s)
- T J Thamann
- Research and Development, Pharmacia and Upjohn, Inc., Kalamazoo, Michigan, 49001, USA
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7
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Peterson FC, Brooks CL. Identification of a motif associated with the lactogenic actions of human growth hormone. J Biol Chem 1997; 272:21444-8. [PMID: 9261160 DOI: 10.1074/jbc.272.34.21444] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Human growth hormone (hGH) stimulates somatogenic and lactogenic actions through the GH and prolactin (PRL) receptors, respectively. In contrast, non-primate GHs stimulate only somatotropic action. Phe44, of the human GH sequence is present in all hormones stimulating lactogenic action and absent in all hormones stimulating only somatotropic action. We speculate that the presence of Phe44 is a feature necessary for specifying lactogenic activity. In this report, the role of Phe44 was investigated by its deletion or substitution with alanine or leucine. Deletion of Phe44 or substitution with leucine did not significantly change the structure of hGH as determined by circular dichroism, absorbance, and fluorescence spectroscopies. In contrast, substitution of alanine perturbed the structure. Deletion of Phe44 reduced binding affinity for the lactogenic receptor, resulting in a reduced activation. Substitution with either alanine or leucine partially restored lactogenic receptor binding affinity, which correlated with the hormones' activity in the Nb2 rat lymphoma cells. All the recombinant hGHs had similar somatotropic activities in FDC-P1 cells transfected with the hGH receptor. These data indicate that the hydrophobic side chain of Phe44 is required for lactogenic receptor binding and activation but is unnecessary for somatotropic action.
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Affiliation(s)
- F C Peterson
- Ohio State Biochemistry Program, Ohio State University, Columbus, Ohio 43210, USA
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Cady SM, Steber WD. Controlled delivery of somatotropins. PHARMACEUTICAL BIOTECHNOLOGY 1997; 10:289-317. [PMID: 9160377 DOI: 10.1007/0-306-46803-4_11] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Affiliation(s)
- S M Cady
- Hoechst Roussel Vet, Somerville, New Jersey 08876-1258, USA
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9
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Pfund WP, Bourdage JS, Farley KA. Structural analysis of bovine somatotropin using monoclonal antibodies and the conformation-sensitive immunoassay. J Biol Chem 1996; 271:14055-61. [PMID: 8662950 DOI: 10.1074/jbc.271.24.14055] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
Bovine somatotropin was studied with respect to thermal stability, quantitative thermal denaturation kinetics, and refolding potential following thermal denaturation using a panel of 6 monoclonal antibodies and the Conformation-Sensitive Immunoassay (CSI). The antibody panel consisted of 4 conformation-dependent and 2 sequence-specific antibodies. Each of the antibodies revealed unique thermal stability profiles for their respective epitopes suggesting that they each recognize different antigenic determinants. Comparing the thermal stability profiles generated with these antibodies allowed the stability of bovine somatotropin to be "dissected" based on individual structural features. The degree to which bovine somatotropin is stabilized by disulfide bonds was examined using CSI-based quantitative thermal denaturation kinetics profiles generated under reducing and nonreducing conditions. All of the conformational epitopes unfolded faster under reducing conditions indicating that the two disulfide bonds within the somatotropin molecule impart some degree of global stabilization. The ability of bovine somatotropin to refold after reducing or nonreducing thermal denaturation was also examined using the antibody panel and the CSI. The results show that, although significant refolding was evident for some epitopes, bovine somatotropin cannot refold to the native state following thermal denaturation under either reducing or nonreducing conditions.
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Affiliation(s)
- W P Pfund
- Analytical Research & Specification Development, Pharmacia & Upjohn, Inc., Kalamazoo, Michigan 49001, USA
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Cardamone M, Puri NK, Sawyer WH, Capon RJ, Brandon MR. A spectroscopic and equilibrium binding analysis of cationic detergent-protein interactions using soluble and insoluble recombinant porcine growth hormone. BIOCHIMICA ET BIOPHYSICA ACTA 1994; 1206:71-82. [PMID: 8186252 DOI: 10.1016/0167-4838(94)90074-4] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Overexpression of cloned eukaryote genes in bacteria often leads to the formation of insoluble refractile bodies which require solubilization by harsh denaturants or detergents. We describe the conformational changes associated with the binding of a surfactant, cetyltrimethylammonium chloride (CTAC) to recombinant porcine growth hormone (PGH). The stoichiometry of binding by CTAC to the soluble and insoluble forms of recombinant PGH was also assessed. Optimum CTAC binding and protein solubilisation were obtained at 50 degrees C and at extreme pH. Increased ionic strength and changes in pH towards the isoelectric point of PGH (pH 6) decreased both the binding of CTAC and the efficiency of solubilising PGH from inclusion bodies. The positive charge on the quaternary ammonium head group of CTAC was found to be critical in the binding of CTAC to PGH and for the subsequent solubilisation of inclusion bodies. The binding of CTAC to the soluble form of PGH caused appreciable changes to the tertiary structure of the protein but did not significantly alter secondary structure, or cause complete unfolding. These observations help to explain earlier results which demonstrate that urea, guanidine hydrochloride and CTAC solubilized recombinant PGH molecules behave differently during in vitro refolding (Puri, N.K., Crivelli, E.C., Cardamone, M., Fiddes, R., Bertolini, J., Ninham, B. and Brandon, M.R. (1992) Biochem. J. 285, 871-879.).
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Affiliation(s)
- M Cardamone
- Centre for Animal Biotechnology, School of Veterinary Science, University of Melbourne, Parkville, Vic., Australia
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12
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Porter WR, Staack H, Brandt K, Manning MC. Thermal stability of low molecular weight urokinase during heat treatment. I. Effects of protein concentration, pH and ionic strength. Thromb Res 1993; 71:265-79. [PMID: 8236156 DOI: 10.1016/0049-3848(93)90196-u] [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: 01/29/2023]
Abstract
Exposure of low molecular weight urokinase (LMW-UK) to prolonged heating (60 degrees C, 10 hours) is used to inactivate possible viral contaminants. This process leads to a significant loss of active enzyme. Amidolytic activity was monitored following heat treatment in order to establish the conditions for maintaining the optimal stability of LMW-UK. The effects of pH, ionic strength, protein concentration, and various ionic additives were examined. While LMW-UK is stable across a wide pH range (pH 2-11), heating LMW-UK in aqueous solution leads to complete loss of activity except between pH 4 and 7.5. The mechanism of inactivation was delineated using activity assays as well as turbimetric and spectroscopic methods. Thermal inactivation occurs via aggregation of unfolded LMW-UK, followed by subsequent precipitation. Threshold effects upon the thermally-induced aggregation of LMW-UK were observed.
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Affiliation(s)
- W R Porter
- Department 493, Abbott Laboratories, Abbott Park, IL 60064
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13
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Egan DA, Logan TM, Liang H, Matayoshi E, Fesik SW, Holzman TF. Equilibrium denaturation of recombinant human FK binding protein in urea. Biochemistry 1993; 32:1920-7. [PMID: 7680574 DOI: 10.1021/bi00059a006] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2023]
Abstract
The equilibrium folding behavior of recombinant human FK-binding protein, a peptidyl-prolyl cis-trans-isomerase, was examined by urea-induced denaturation using probes of protein structure including intrinsic tryptophan fluorescence, second-derivative UV absorbance, CD, and NMR. All optical probes of protein structure indicate that FKBP is capable of folding reversibly. The second-derivative UV absorbance and CD probes of the structure exhibited urea denaturation transitions at approximately 4.3 M urea. The fluorescence of the single protein tryptophan is quenched in the folded state. During the unfolding-folding transition, the unquenching of tryptophan fluorescence occurs at a slightly lower urea concentration (3.9 M urea) than the changes observed for the other optical probes of folding. These probes of structure demonstrate little dependence on protein concentration in the range of 0.2- approximately 3 mg/mL across the urea-induced denaturation transition. The reversibility of the unfolding-folding transition was confirmed from two-dimensional 15N/1H heteronuclear single-quantum coherence (HSQC) spectra of [U-15N]FKBP. In addition, the native-denatured transitions for 57 individual amino acids were determined from an analysis of these spectra acquired at different urea concentrations. Analysis of the transitions for all clearly observable HSQC cross peaks for residues distributed throughout the protein and comparison to the optical folding transitions, indicate that FKBP global folding is consistent with a two-state process. Although direct measurement of FKBP catalytic activity in urea was complex, enzyme activity was observed up to the beginning of the FKBP urea-denaturation transition.(ABSTRACT TRUNCATED AT 250 WORDS)
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Affiliation(s)
- D A Egan
- Pharmaceutical Products Division, Abbott Laboratories, Abbott Park, Illinois 60064
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Fridman M, Aguilar MI, Hearn MT. High-performance liquid chromatography of amino acids, peptides and proteins. XCIX. Comparative study of the equilibrium refolding of bovine, porcine and human growth hormone by size-exclusion chromatography. J Chromatogr A 1990; 512:57-75. [PMID: 2229238 DOI: 10.1016/s0021-9673(01)89473-5] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The equilibrium refolding of bovine, porcine and human growth hormone and ovine prolactin in guanidine hydrochloride has been investigated using high-performance size-exclusion chromatography (HPSEC). It was found that bovine and porcine growth hormones exhibited very similar refolding behaviour. However, the renaturation of human growth hormone followed a different pathway. In particular, the folding transition of human growth hormone occurred at 4.7 M guanidine hydrochloride compared to 3.8 and 3.5 M for the bovine and porcine molecules, respectively, and 3.5 M for ovine prolactin. The refolding mechanism of an internally clipped fragment derived from partial tryptic digestion, exhibited similar folding properties to the corresponding intact molecule. The internally clipped analogue existed as a relatively larger molecule under fully denaturing conditions. Reduction followed by carboxymethylation resulted in growth hormone molecules with significantly reduced stability and altered folding properties. The results have been correlated with differences in structure to further demonstrate the utility of HPSEC in the study of protein folding and stability.
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Affiliation(s)
- M Fridman
- Department of Biochemistry, Monash University, Clayton, Victoria, Australia
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15
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Pfund WP, Bourdage JS. The conformation-sensitive immunoassay: a membrane based ELISA system for identifying antibodies sensitive to alterations of protein conformation. Mol Immunol 1990; 27:495-502. [PMID: 2166235 DOI: 10.1016/0161-5890(90)90068-b] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
A Conformation-Sensitive Immunoassay (CSI) has been developed for identification of antibodies that are sensitive to alterations in protein conformation. The method involves covalently coupling proteins to an activated hydrophilic membrane support. The membrane bound proteins are then treated under conditions known to alter protein conformation, immobilized in a non-native state via additional covalent interactions with the support, and subsequently probed using conventional ELISA techniques. This method has been validated using several well characterized conformation-sensitive antibodies to horse cytochrome c and sperm whale myoglobin. A panel of monoclonal antibodies directed against bovine somatotropin (bSt) has been partially characterized using this validated CSI procedure. Each of these antibodies to bSt has been shown to detect conformational alterations of bSt structure. Data are also presented that demonstrates that the accuracy of CSI analysis is superior to that of Western blotting for characterizing conformation-sensitive antibodies.
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Affiliation(s)
- W P Pfund
- Control Biotechnology Development, Upjohn Company, Kalamazoo, MI 49001
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16
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Brems DN, Brown PL, Becker GW. Equilibrium denaturation of human growth hormone and its cysteine-modified forms. J Biol Chem 1990. [DOI: 10.1016/s0021-9258(19)39390-1] [Citation(s) in RCA: 56] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
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Affiliation(s)
- B Mao
- Upjohn Research Laboratories, Kalamazoo, MI 49001
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18
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Abstract
Recombinant DNA technology has now made it possible to produce proteins for pharmaceutical applications. Consequently, proteins produced via biotechnology now comprise a significant portion of the drugs currently under development. Isolation, purification, formulation, and delivery of proteins represent significant challenges to pharmaceutical scientists, as proteins possess unique chemical and physical properties. These properties pose difficult stability problems. A summary of both chemical and physical decomposition pathways for proteins is given. Chemical instability can include proteolysis, deamidation, oxidation, racemization, and beta-elimination. Physical instability refers to processes such as aggregation, precipitation, denaturation, and adsorption to surfaces. Current methodology to stabilize proteins is presented, including additives, excipients, chemical modification, and the use of site-directed mutagenesis to produce a more stable protein species.
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Affiliation(s)
- M C Manning
- Department of Pharmaceutical Chemistry, University of Kansas, Lawrence 66045
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19
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Violand BN, Takano M, Curran DF, Bentle LA. A novel concatenated dimer of recombinant bovine somatotropin. JOURNAL OF PROTEIN CHEMISTRY 1989; 8:619-28. [PMID: 2692595 DOI: 10.1007/bf01025602] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
A novel protein concatenated dimer structure was generated during the folding/oxidation of inclusion bodies of recombinant bovine somatotropin synthesized in Escherichia coli. The structure of this dimeric molecule was determined by peptide mapping with trypsin, and limited proteolysis by thrombin. Peptide mapping demonstrated that the two disulfide pairs in bovine somatotropin dimer were identical to those in monomer. Limited proteolysis with thrombin resulted in the cleavage of only a single peptide bond between arginine-132 and alanine-133 in bovine somatotropin dimer. This single peptide bond cleavage was sufficient to convert this dimer to a monomeric molecular weight species as analyzed by sodium dodecyl sulfate polyacrylamide gel electrophoresis and HPLC. Since the single cleaved peptide bond is present in the large disulfide loop of bovine somatotropin, these data demonstrate that the dimeric molecule exists as a novel concatenated structure through the interlocking of the disulfide loops of this protein.
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Affiliation(s)
- B N Violand
- Animal Sciences Division, Monsanto Corporation, St. Louis, Missouri 63198
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Ikeguchi M, Sugai S. Contribution of disulfide bonds to stability of the folding intermediate of alpha-lactalbumin. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1989; 33:289-97. [PMID: 2753599 DOI: 10.1111/j.1399-3011.1989.tb01284.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
The secondary structure formed in disulfide reduced alpha-lactalbumin is investigated by CD spectrum and is compared with that of the folding intermediate of the disulfide intact protein. The peptide backbone structure of the reduced protein depends strongly on salt concentration in contrast to that of the intermediate. It is close to a random coil in the absence of salt, but it is almost the same as that of the intermediate at a high concentration of salt. The secondary structures of both the proteins undergo broad unfolding transitions when temperature is raised or when urea is added. The secondary structure of the reduced protein is less stable against both heat and urea. These results show that the disulfide bonds are not a determinant of the secondary structure formed at an early stage of folding, and they stabilize the secondary structure of the folding intermediate.
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Affiliation(s)
- M Ikeguchi
- Department of Polymer Science, Faculty of Science, Hokkaido University, Sapporo, Japan
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21
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Petrides D, Cooney CL, Evans LB, Field RP, Snoswell M. Bioprocess simulation: An integrated approach to process development. Comput Chem Eng 1989. [DOI: 10.1016/0098-1354(89)85038-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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Burton SJ, Quirk AV, Wood PC. Refolding human serum albumin at relatively high protein concentration. EUROPEAN JOURNAL OF BIOCHEMISTRY 1989; 179:379-87. [PMID: 2917571 DOI: 10.1111/j.1432-1033.1989.tb14564.x] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
The conditions for refolding reduced and denatured human serum albumin (HSA) were investigated with a view to maximising the yield of native monomeric albumin. Refolding by dialysis was found to be preferable to dilution as a means of chaotrope (urea) and reductant (2-mercaptoethanol) removal. Dialysis of denatured HSA solutions containing 4-8 M urea and 14 mM 2-mercaptoethanol at pH 10.0 was found to be optimal for HSA refolding. The yield of monomeric HSA was maximal (94%) for dialysis in the presence of EDTA (1 mM) and sodium palmitate (20 microM). Using this protocol it was possible to refold HSA at concentrations in excess of 5 mg.ml-1 whilst maintaining a high recovery of native monomer. These results represent a considerable improvement on established methods of HSA refolding.
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Affiliation(s)
- S J Burton
- Delta Biotechnology Ltd, Nottingham, England
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23
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Kuwajima K. The molten globule state as a clue for understanding the folding and cooperativity of globular-protein structure. Proteins 1989; 6:87-103. [PMID: 2695928 DOI: 10.1002/prot.340060202] [Citation(s) in RCA: 1121] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Affiliation(s)
- K Kuwajima
- Department of Polymer Science, Faculty of Science, Hokkaido University, Japan
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Ermácora MR, Rivero JL. Secondary structure prediction of 11 mammalian growth hormones. INTERNATIONAL JOURNAL OF PEPTIDE AND PROTEIN RESEARCH 1988; 32:223-9. [PMID: 3243668 DOI: 10.1111/j.1399-3011.1988.tb00937.x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/04/2023]
Abstract
The secondary structure of 11 mammalian growth hormones has been predicted by combining five different methods. Three long helical regions located around residues 20, 120, and 170 constitute the most prominent common feature in the species studied. The strong amphiphilic character of these helices suggests that they can play an important role in protein folding or stability.
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Affiliation(s)
- M R Ermácora
- Institute of Biochemistry and Biophysicochemistry (UBA-CONICET), Faculty of Pharmacy and Biochemistry, Buenos Aires, Argentina
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25
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Hearn MT, Aguilar MI, Nguyen T, Fridman M. High-performance liquid chromatography of amino acids, peptides and proteins. LXXXIV. Application of derivative spectroscopy to the study of column residency effects in the reversed-phase and size-exclusion liquid chromatographic separation of proteins. J Chromatogr A 1988; 435:271-84. [PMID: 3346342 DOI: 10.1016/s0021-9673(01)82187-7] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The influence of column residency times on the reversed-phase gradient elution behaviour of human and bovine growth hormones has been investigated using on-line photodiode array spectroscopic detection. Stationary phase induced effects on protein conformation were monitored by changes in the maxima to minima ratio of the second derivative spectrum of the eluted protein. Significant changes in the second derivative ratio of the unmodified and the fully reduced and alkylated protein were observed following long incubation times, i.e. t(dwell) greater than 15 min, at the stationary phase surface in the presence of 0.1% trifluoroacetic acid before elution with a 0-75% aqueous acetonitrile gradient. The application of multi-wavelength detection in the study of equilibrium unfolding of growth hormones in urea by size-exclusion chromatography was also investigated. On-line photodiode array instrumentation and derivative spectra rationing was employed to monitor tertiary and quaternary structural changes associated with protein denaturation during a chromatographic separation. These studies clearly demonstrate the powerful detection capabilities of such instrumental approaches for the on-line evaluation of both stationary phase surface and/or mobile phase mediated changes in protein conformation.
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Affiliation(s)
- M T Hearn
- Department of Biochemistry, Monash University, Clayton, Victoria, Australia
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