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Persson, Malin
Publications (7 of 7) Show all publications
Villebeck, L., Persson, M., Luan, S.-L., Hammarström, P., Lindgren, M. & Jonsson, B.-H. (2007). Conformational Rearrangements of Tail-less Complex Polypeptide 1 (TCP-1) Ring Complex (TRiC)-Bound Actin. Biochemistry, 46(17), 5083-5093
Open this publication in new window or tab >>Conformational Rearrangements of Tail-less Complex Polypeptide 1 (TCP-1) Ring Complex (TRiC)-Bound Actin
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2007 (English)In: Biochemistry, ISSN 0006-2960, Vol. 46, no 17, p. 5083-5093Article in journal (Refereed) Published
Abstract [en]

The mechanism of chaperonins is still under intense investigation. Earlier studies by others and us on the bacterial chaperonin GroEL points to an active role of chaperonins in unfolding the target protein during initial binding. Here, a natural eukaryotic chaperonin system [tail-less complex polypeptide 1 (TCP-1) ring complex (TRiC) and its target protein actin] was investigated to determine if the active participation of the chaperonin in the folding process is evolutionary-conserved. Using fluorescence resonance energy transfer (FRET) measurements on four distinct doubly fluorescein-labeled variants of actin, we have obtained a fairly detailed map of the structural rearrangements that occur during the TRiC−actin interaction. The results clearly show that TRiC has an active role in rearranging the bound actin molecule. The target is stretched as a consequence of binding to TRiC and further rearranged in a second step as a consequence of ATP binding; i.e., the mechanism of chaperonins is conserved during evolution.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-13123 (URN)10.1021/bi062093o (DOI)
Available from: 2008-04-03 Created: 2008-04-03 Last updated: 2018-04-25
Rodlert, M., Vestberg, R., Malmstrom, E., Persson, M. & Lindgren, M. (2002). Chiral dendritic polymers for photonic applications. Synthetic metals, 127(1-3)
Open this publication in new window or tab >>Chiral dendritic polymers for photonic applications
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2002 (English)In: Synthetic metals, ISSN 0379-6779, E-ISSN 1879-3290, Vol. 127, no 1-3, p. 37-43Conference paper, Published paper (Other academic)
Abstract [en]

We present chiral dendrons of different generations accomplished by reacting the hydroxyl groups at the chain ends with (-)menthoxyacetic acid. Subsequent deprotection of the carboxylic acid rendered acid functional chiral dendrons. The acid-functionalized chiral dendrons were doped with divalent cations Cu2+, Fe2+ and Zn2+, and trivalent lanthanide cations Nd3+ and Pr3+. We present results on their optical rotatory power along with circular dichroism spectroscopy and results of paramagnetic resonance. The chiral dendrons were shown to influence the electronic transitions of the metal ions (CD spectra). Attempts to characterize the circularly polarized luminescence of the Nd-dendrimer failed due to low quantum yield. The luminescence efficiency was found to be at least one order of magnitude lower than that of a fluorinated and non-chiral dendrimer structure of similar size and coordination structure. © 2002 Elsevier Science B.V. All rights reserved.

Keywords
Chiral, Circular dichroism, Dendritic polymer
National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-47056 (URN)10.1016/S0379-6779(01)00585-9 (DOI)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2017-12-13
Persson, M., Harbridge, J., Hammarström, P., Mitri, R., Mårtensson, L.-G., Carlsson, U., . . . Eaton, S. (2001). Comparison of electron paramagnetic resonance methods to determine distances between spin labels on human carbonic anhydrase II. Biophysical Journal, 80(6), 2886-2897
Open this publication in new window or tab >>Comparison of electron paramagnetic resonance methods to determine distances between spin labels on human carbonic anhydrase II
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2001 (English)In: Biophysical Journal, ISSN 0006-3495, E-ISSN 1542-0086, Vol. 80, no 6, p. 2886-2897Article in journal (Refereed) Published
Abstract [en]

Four doubly spin-labeled variants of human carbonic anhydrase II and corresponding singly labeled variants were prepared by site-directed spin labeling. The distances between the spin labels were obtained from continuous-wave electron paramagnetic resonance spectra by analysis of the relative intensity of the half-field transition, Fourier deconvolution of line-shape broadening, and computer simulation of line-shape changes. Distances also were determined by four-pulse double electron-electron resonance. For each variant, at least two methods were applicable and reasonable agreement between methods was obtained. Distances ranged from 7 to 24 W. The doubly spin-labeled samples contained some singly labeled protein due to incomplete labeling. The sensitivity of each of the distance determination methods to the noninteracting component was compared.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-49243 (URN)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2018-04-25
Hammarström, P., Persson, M. & Carlsson, U. (2001). Protein compactness measured by fluorescence resonance energy transfer - Human carbonic anhydrase II Is considerably expanded by the interaction of GroEL. Journal of Biological Chemistry, 276(24), 21765-21775
Open this publication in new window or tab >>Protein compactness measured by fluorescence resonance energy transfer - Human carbonic anhydrase II Is considerably expanded by the interaction of GroEL
2001 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 276, no 24, p. 21765-21775Article in journal (Refereed) Published
Abstract [en]

Nine single-cysteine mutants were labeled with 5-(2-iodoacetylaminoethylamino)naphthalene-1-sulfonic acid, an efficient acceptor of Trp fluorescence in fluorescence resonance energy transfer. The ratio between the fluorescence intensity of the 5-(2-acetylaminoethylamino)naphthalene-1-sulfonic acid (AEDANS) moiety excited at 295 nm (Trp absorption) and 350 nn (direct AEDANS absorption) was used to estimate the average distances between the seven Trp residues in human carbonic anhydrase II (HCA II) and the AEDANS label, Guanidine HCl denaturation of the HCA II variants was also performed to obtain a curve that reflected the compactness of the protein at various stages of the unfolding, which could serve as a scale of the expansion of the protein. This approach was developed in this study and was used to estimate the compactness of HCA II during heat denaturation and interaction with GroEL, It was shown that thermally induced unfolding of HCA II proceeded only to the molten globule state. Reaching this state was sufficient to allow HCA II to bind to GroEL, and the volume of the molten globule intermediate increased similar to2.2-fold compared with that of the native state. GroEL-bound HCA II expands to a volume three to four times that of the native state (to similar to 117,000 Angstrom (3)), which correlates well with a stretched and loosened-up HCA II molecule in an enlarged GroEL cavity, Recently, we found that HCA II binding causes such an inflation of the GroEL molecule, and this probably represents the mechanism by which GroEL actively stretches its protein substrates apart (Hammarstrom, P., Persson, M., Owenius, R., Lindgren, M., and Carlsson, U. (2000) J. Biol. Chem. 275, 22832-22838), thereby facilitating rearrangement of misfolded structure.

National Category
Engineering and Technology
Identifiers
urn:nbn:se:liu:diva-49220 (URN)
Available from: 2009-10-11 Created: 2009-10-11 Last updated: 2018-04-25
Hammarström, P., Persson, M., Owenius, R., Lindgren, M. & Carlsson, U. (2000). Protein substrate binding induces conformational changes in the chaperonin GroEL: A suggested mechanism for unfoldase activity. Journal of Biological Chemistry, 275(30), 22832-22838
Open this publication in new window or tab >>Protein substrate binding induces conformational changes in the chaperonin GroEL: A suggested mechanism for unfoldase activity
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2000 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 275, no 30, p. 22832-22838Article in journal (Refereed) Published
Abstract [en]

Chaperonins are molecules that assist proteins during folding and protect them from irreversible aggregation. We studied the chaperonin GroEL and its interaction with the enzyme human carbonic anhydrase II (HCA II), which induces unfolding of the enzyme. We focused on conformational changes that occur in GroEL during formation of the GroEL-HCA II complex. We measured the rate of GroEL cysteine reactivity toward iodo[2-(14)C]acetic acid and found that the cysteines become more accessible during binding of a cysteine free mutant of HCA II. Spin labeling of GroEL with N-(1-oxy1-2,2,5,5-tetramethyl-3-pyrrolidinyl)iodoacetamide revealed that this additional binding occurred because buried cysteine residues become accessible during HCA II binding. In addition, a GroEL variant labeled with 6-iodoacetamidofluorescein exhibited decreased fluorescence anisotropy upon HCA II binding, which resembles the effect of GroES/ATP binding. Furthermore, by producing cysteine-modified GroEL with the spin label N-(1-oxyl-2,2,5,5-tetramethyl-3-pyrrolidinyl)iodoacetamide and the fluorescent label 5-((((2-iodoacetyl)amino)ethyl)amino)naphthalene-1-sulfonic acid, we detected increases in spin-label mobility and fluorescence intensity in GroEL upon HCA II binding. Together, these results show that conformational changes occur in the chaperonin as a consequence of protein substrate binding. Together with previous results on the unfoldase activity of GroEL, we suggest that the chaperonin opens up as the substrate protein binds. This opening mechanism may induce stretching of the protein, which would account for reported unfoldase activity of GroEL and might explain how GroEL can actively chaperone proteins larger than HCA II.

National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-42081 (URN)10.1074/jbc.M000649200 (DOI)60241 (Local ID)60241 (Archive number)60241 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-04-25
Persson, M., Hammarström, P., Lindgren, M., Jonsson, B.-H., Svensson, M. & Carlsson, U. (1999). EPR Mapping of Interactions Between Spin-labeled Variants of Human Carbonic Anhydrase II and GroEL. Evidence for increased flexibility of the hydrophobic core by the interaction.. Biochemistry, 38, 432-441
Open this publication in new window or tab >>EPR Mapping of Interactions Between Spin-labeled Variants of Human Carbonic Anhydrase II and GroEL. Evidence for increased flexibility of the hydrophobic core by the interaction.
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1999 (English)In: Biochemistry, ISSN 0006-2960, E-ISSN 1520-4995, Vol. 38, p. 432-441Article in journal (Refereed) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-42071 (URN)60198 (Local ID)60198 (Archive number)60198 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-04-25
Hammarström, P., Persson, M., Freskgård, P.-O., Mårtensson, L.-G., Andersson, D., Jonsson, B.-H. & Carlsson, U. (1999). Structural mapping of an aggregation nucleation site in a molten-globule intermediate. Journal of Biological Chemistry, 274, 32897-32903
Open this publication in new window or tab >>Structural mapping of an aggregation nucleation site in a molten-globule intermediate
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1999 (English)In: Journal of Biological Chemistry, ISSN 0021-9258, E-ISSN 1083-351X, Vol. 274, p. 32897-32903Article in journal (Refereed) Published
National Category
Natural Sciences
Identifiers
urn:nbn:se:liu:diva-42070 (URN)60197 (Local ID)60197 (Archive number)60197 (OAI)
Available from: 2009-10-10 Created: 2009-10-10 Last updated: 2018-04-25
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