Webbläsaren som du använder stöds inte av denna webbplats. Alla versioner av Internet Explorer stöds inte längre, av oss eller Microsoft (läs mer här: * https://www.microsoft.com/en-us/microsoft-365/windows/end-of-ie-support).

Var god och använd en modern webbläsare för att ta del av denna webbplats, som t.ex. nyaste versioner av Edge, Chrome, Firefox eller Safari osv.

Conformational analysis of HAMLET, the folding variant of human alpha-lactalbumin associated with apoptosis

Författare

  • A Casbarra
  • L Birolo
  • G Infusini
  • F DAL Piaz
  • M Svensson
  • P Pucci
  • Catharina Svanborg
  • G Marino

Summary, in English

A combination of hydrogen/deuterium (H/D) exchange and limited proteolysis experiments coupled to mass spectrometry analysis was used to depict the conformation in solution of HAMLET, the folding variant of human alpha-lactalbumin, complexed to oleic acid, that induces apoptosis in tumor and immature cells. Although near- and far-UV CD and fluorescence spectroscopy were not able to discriminate between HAMLET and apo-alpha-lactalbumin, H/D exchange experiments clearly showed that they correspond to two distinct conformational states, with HAMLET incorporating a greater number of deuterium atoms than the apo and holo forms. Complementary proteolysis experiments revealed that HAMLET and apo are both accessible to proteases in the P-domain but showed substantial differences in accessibility to proteases at specific sites. The overall results indicated that the conformational changes associated with the release of Ca2+ are not sufficient to induce the HAMLET conformation. Metal depletion might represent the first event to produce a partial unfolding in the beta-domain of a-lactalbumin, but some more unfolding is needed to generate the active conformation HAMLET, very likely allowing the protein to bind the C18:1 fatty acid moiety. On the basis of these data, a putative binding site of the oleic acid, which stabilizes the HAMLET conformation, is proposed.

Publiceringsår

2004

Språk

Engelska

Sidor

1322-1330

Publikation/Tidskrift/Serie

Protein Science

Volym

13

Issue

5

Dokumenttyp

Artikel i tidskrift

Förlag

The Protein Society

Ämne

  • Immunology in the medical area
  • Microbiology in the medical area

Nyckelord

  • limited proteolysis
  • H/D exchange
  • conformational analysis
  • HAMLET
  • alpha-lactalbumin

Status

Published

ISBN/ISSN/Övrigt

  • ISSN: 1469-896X