Thermal dissociation and unfolding of insulin

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Thermal dissociation and unfolding of insulin. / Huus, Kasper; Havelund, Svend; Olsen, Helle B; van de Weert, Marco; Frokjaer, Sven.

In: Biochemistry, Vol. 44, No. 33, 23.08.2005, p. 11171-7.

Research output: Contribution to journalJournal articleResearchpeer-review

Harvard

Huus, K, Havelund, S, Olsen, HB, van de Weert, M & Frokjaer, S 2005, 'Thermal dissociation and unfolding of insulin', Biochemistry, vol. 44, no. 33, pp. 11171-7. https://doi.org/10.1021/bi0507940

APA

Huus, K., Havelund, S., Olsen, H. B., van de Weert, M., & Frokjaer, S. (2005). Thermal dissociation and unfolding of insulin. Biochemistry, 44(33), 11171-7. https://doi.org/10.1021/bi0507940

Vancouver

Huus K, Havelund S, Olsen HB, van de Weert M, Frokjaer S. Thermal dissociation and unfolding of insulin. Biochemistry. 2005 Aug 23;44(33):11171-7. https://doi.org/10.1021/bi0507940

Author

Huus, Kasper ; Havelund, Svend ; Olsen, Helle B ; van de Weert, Marco ; Frokjaer, Sven. / Thermal dissociation and unfolding of insulin. In: Biochemistry. 2005 ; Vol. 44, No. 33. pp. 11171-7.

Bibtex

@article{f07b812b29a24dc0a27fb78d524e8d50,
title = "Thermal dissociation and unfolding of insulin",
abstract = "The thermal stability of human insulin was studied by differential scanning microcalorimetry and near-UV circular dichroism as a function of zinc/protein ratio, to elucidate the dissociation and unfolding processes of insulin in different association states. Zinc-free insulin, which is primarily dimeric at room temperature, unfolded at approximately 70 degrees C. The two monomeric insulin mutants Asp(B28) and Asp(B9),Glu(B27) unfolded at higher temperatures, but with enthalpies of unfolding that were approximately 30{\%} smaller. Small amounts of zinc caused a biphasic thermal denaturation pattern of insulin. The biphasic denaturation is caused by a redistribution of zinc ions during the heating process and results in two distinct transitions with T(m)'s of approximately 70 and approximately 87 degrees C corresponding to monomer/dimer and hexamer, respectively. At high zinc concentrations (>or=5 Zn(2+) ions/hexamer), only the hexamer transition is observed. The results of this study show that the thermal stability of insulin is closely linked to the association state and that the zinc hexamer remains stable at much higher temperatures than the monomer. This is in contrast to studies with chemical denaturants where it has been shown that monomer unfolding takes place at much higher denaturant concentrations than the dissociation of higher oligomers [Ahmad, A., et al. (2004) J. Biol. Chem. 279, 14999-15013].",
keywords = "Amino Acid Substitution, Calorimetry, Differential Scanning, Circular Dichroism, Hot Temperature, Humans, Insulin, Point Mutation, Protein Denaturation, Protein Folding, Zinc",
author = "Kasper Huus and Svend Havelund and Olsen, {Helle B} and {van de Weert}, Marco and Sven Frokjaer",
year = "2005",
month = "8",
day = "23",
doi = "10.1021/bi0507940",
language = "English",
volume = "44",
pages = "11171--7",
journal = "Biochemistry",
issn = "0006-2960",
publisher = "American Chemical Society",
number = "33",

}

RIS

TY - JOUR

T1 - Thermal dissociation and unfolding of insulin

AU - Huus, Kasper

AU - Havelund, Svend

AU - Olsen, Helle B

AU - van de Weert, Marco

AU - Frokjaer, Sven

PY - 2005/8/23

Y1 - 2005/8/23

N2 - The thermal stability of human insulin was studied by differential scanning microcalorimetry and near-UV circular dichroism as a function of zinc/protein ratio, to elucidate the dissociation and unfolding processes of insulin in different association states. Zinc-free insulin, which is primarily dimeric at room temperature, unfolded at approximately 70 degrees C. The two monomeric insulin mutants Asp(B28) and Asp(B9),Glu(B27) unfolded at higher temperatures, but with enthalpies of unfolding that were approximately 30% smaller. Small amounts of zinc caused a biphasic thermal denaturation pattern of insulin. The biphasic denaturation is caused by a redistribution of zinc ions during the heating process and results in two distinct transitions with T(m)'s of approximately 70 and approximately 87 degrees C corresponding to monomer/dimer and hexamer, respectively. At high zinc concentrations (>or=5 Zn(2+) ions/hexamer), only the hexamer transition is observed. The results of this study show that the thermal stability of insulin is closely linked to the association state and that the zinc hexamer remains stable at much higher temperatures than the monomer. This is in contrast to studies with chemical denaturants where it has been shown that monomer unfolding takes place at much higher denaturant concentrations than the dissociation of higher oligomers [Ahmad, A., et al. (2004) J. Biol. Chem. 279, 14999-15013].

AB - The thermal stability of human insulin was studied by differential scanning microcalorimetry and near-UV circular dichroism as a function of zinc/protein ratio, to elucidate the dissociation and unfolding processes of insulin in different association states. Zinc-free insulin, which is primarily dimeric at room temperature, unfolded at approximately 70 degrees C. The two monomeric insulin mutants Asp(B28) and Asp(B9),Glu(B27) unfolded at higher temperatures, but with enthalpies of unfolding that were approximately 30% smaller. Small amounts of zinc caused a biphasic thermal denaturation pattern of insulin. The biphasic denaturation is caused by a redistribution of zinc ions during the heating process and results in two distinct transitions with T(m)'s of approximately 70 and approximately 87 degrees C corresponding to monomer/dimer and hexamer, respectively. At high zinc concentrations (>or=5 Zn(2+) ions/hexamer), only the hexamer transition is observed. The results of this study show that the thermal stability of insulin is closely linked to the association state and that the zinc hexamer remains stable at much higher temperatures than the monomer. This is in contrast to studies with chemical denaturants where it has been shown that monomer unfolding takes place at much higher denaturant concentrations than the dissociation of higher oligomers [Ahmad, A., et al. (2004) J. Biol. Chem. 279, 14999-15013].

KW - Amino Acid Substitution

KW - Calorimetry, Differential Scanning

KW - Circular Dichroism

KW - Hot Temperature

KW - Humans

KW - Insulin

KW - Point Mutation

KW - Protein Denaturation

KW - Protein Folding

KW - Zinc

U2 - 10.1021/bi0507940

DO - 10.1021/bi0507940

M3 - Journal article

C2 - 16101301

VL - 44

SP - 11171

EP - 11177

JO - Biochemistry

JF - Biochemistry

SN - 0006-2960

IS - 33

ER -

ID: 44640563