Calcium binding and disulfide bonds regulate the stability of Secretagogin towards thermal and urea denaturation

Forskningsoutput: TidskriftsbidragArtikel i vetenskaplig tidskrift

Abstract

Secretagogin is a calcium-sensor protein with six EF-hands. It is widely expressed in neurons and neuro-endocrine cells of a broad range of vertebrates including mammals, fishes and amphibia. The protein plays a role in secretion and interacts with several vesicle-associated proteins. In this work, we have studied the contribution of calcium binding and disulfide-bond formation to the stability of the secretagogin structure towards thermal and urea denaturation. SDS-PAGE analysis of secretagogin in reducing and non-reducing conditions identified a tendency of the protein to form dimers in a redox-dependent manner. The denaturation of apo and Calcium-loaded secretagogin was studied by circular dichroism and fluorescence spectroscopy under conditions favoring monomer or dimer or a 1:1 monomer: dimer ratio. This analysis reveals significantly higher stability towards urea denaturation of Calcium-loaded secretagogin compared to the apo protein. The secondary and tertiary structure of the Calcium-loaded form is not completely denatured in the presence of 10 M urea. Reduced and Calcium-loaded secretagogin is found to refold reversibly after heating to 95°C, while both oxidized and reduced apo secretagogin is irreversibly denatured at this temperature. Thus, calcium binding greatly stabilizes the structure of secretagogin towards chemical and heat denaturation.

Detaljer

Författare
Enheter & grupper
Externa organisationer
  • University College Dublin
Forskningsområden

Ämnesklassifikation (UKÄ) – OBLIGATORISK

  • Biokemi och molekylärbiologi
Originalspråkengelska
Artikelnummere0165709
TidskriftPLoS ONE
Volym11
Utgivningsnummer11
StatusPublished - 2016 nov 1
PublikationskategoriForskning
Peer review utfördJa

Relaterad forskningsoutput

Weiffert, T., 2018 okt, Lund: Media-Tryck, Lund University, Sweden. 244 s.

Forskningsoutput: AvhandlingDoktorsavhandling (sammanläggning)

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