Molecular characterization of alpha-lactalbumin folding variants that induce apoptosis in tumor cells
(1999) In Journal of Biological Chemistry 274(10). p.96-6388- Abstract
This study characterized a protein complex in human milk that induces apoptosis in tumor cells but spares healthy cells. The active fraction was purified from casein by anion exchange chromatography. Unlike other casein components the active fraction was retained by the ion exchanger and eluted after a high salt gradient. The active fraction showed N-terminal amino acid sequence identity with human milk alpha-lactalbumin and mass spectrometry ruled out post-translational modifications. Size exclusion chromatography resolved monomers and oligomers of alpha-lactalbumin that were characterized using UV absorbance, fluorescence, and circular dichroism spectroscopy. The high molecular weight oligomers were kinetically stable against... (More)
This study characterized a protein complex in human milk that induces apoptosis in tumor cells but spares healthy cells. The active fraction was purified from casein by anion exchange chromatography. Unlike other casein components the active fraction was retained by the ion exchanger and eluted after a high salt gradient. The active fraction showed N-terminal amino acid sequence identity with human milk alpha-lactalbumin and mass spectrometry ruled out post-translational modifications. Size exclusion chromatography resolved monomers and oligomers of alpha-lactalbumin that were characterized using UV absorbance, fluorescence, and circular dichroism spectroscopy. The high molecular weight oligomers were kinetically stable against dissociation into monomers and were found to have an essentially retained secondary structure but a less well organized tertiary structure. Comparison with native monomeric and molten globule alpha-lactalbumin showed that the active fraction contains oligomers of alpha-lactalbumin that have undergone a conformational switch toward a molten globule-like state. Oligomerization appears to conserve alpha-lactalbumin in a state with molten globule-like properties at physiological conditions. The results suggest differences in biological properties between folding variants of alpha-lactalbumin.
(Less)
- author
- Svensson, Malin LU ; Sabharwal, H ; Håkansson, Anders P LU ; Mossberg, A K LU ; Lipniunas, P ; Leffler, H LU ; Svanborg, C LU and Linse, S LU
- organization
- publishing date
- 1999-03-05
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Amino Acid Sequence, Apoptosis, Dimerization, Female, Humans, Lactalbumin, Milk, Human, Molecular Sequence Data, Neoplasms, Protein Folding, Structure-Activity Relationship
- in
- Journal of Biological Chemistry
- volume
- 274
- issue
- 10
- pages
- 9 pages
- publisher
- American Society for Biochemistry and Molecular Biology
- external identifiers
-
- pmid:10037730
- scopus:0033525523
- ISSN
- 0021-9258
- DOI
- 10.1074/jbc.274.10.6388
- language
- English
- LU publication?
- yes
- id
- 8d1219fd-cf71-42bd-9552-5e00aecd7a54
- date added to LUP
- 2016-05-21 11:28:52
- date last changed
- 2024-09-06 13:40:53
@article{8d1219fd-cf71-42bd-9552-5e00aecd7a54, abstract = {{<p>This study characterized a protein complex in human milk that induces apoptosis in tumor cells but spares healthy cells. The active fraction was purified from casein by anion exchange chromatography. Unlike other casein components the active fraction was retained by the ion exchanger and eluted after a high salt gradient. The active fraction showed N-terminal amino acid sequence identity with human milk alpha-lactalbumin and mass spectrometry ruled out post-translational modifications. Size exclusion chromatography resolved monomers and oligomers of alpha-lactalbumin that were characterized using UV absorbance, fluorescence, and circular dichroism spectroscopy. The high molecular weight oligomers were kinetically stable against dissociation into monomers and were found to have an essentially retained secondary structure but a less well organized tertiary structure. Comparison with native monomeric and molten globule alpha-lactalbumin showed that the active fraction contains oligomers of alpha-lactalbumin that have undergone a conformational switch toward a molten globule-like state. Oligomerization appears to conserve alpha-lactalbumin in a state with molten globule-like properties at physiological conditions. The results suggest differences in biological properties between folding variants of alpha-lactalbumin.</p>}}, author = {{Svensson, Malin and Sabharwal, H and Håkansson, Anders P and Mossberg, A K and Lipniunas, P and Leffler, H and Svanborg, C and Linse, S}}, issn = {{0021-9258}}, keywords = {{Amino Acid Sequence; Apoptosis; Dimerization; Female; Humans; Lactalbumin; Milk, Human; Molecular Sequence Data; Neoplasms; Protein Folding; Structure-Activity Relationship}}, language = {{eng}}, month = {{03}}, number = {{10}}, pages = {{96--6388}}, publisher = {{American Society for Biochemistry and Molecular Biology}}, series = {{Journal of Biological Chemistry}}, title = {{Molecular characterization of alpha-lactalbumin folding variants that induce apoptosis in tumor cells}}, url = {{http://dx.doi.org/10.1074/jbc.274.10.6388}}, doi = {{10.1074/jbc.274.10.6388}}, volume = {{274}}, year = {{1999}}, }