α-Lactalbumin, Amazing Calcium-Binding Protein
α-Lactalbumin (α-LA) is a small (Mr 14,200), acidic (pI 4–5), Ca<sup>2+</sup>-binding protein. α-LA is a regulatory component of lactose synthase enzyme system functioning in the lactating mammary gland. The protein possesses a single strong Ca<sup>2+</sup>-binding site, whic...
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| Format: | Article |
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MDPI AG
2020-08-01
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| Series: | Biomolecules |
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| Online Access: | https://www.mdpi.com/2218-273X/10/9/1210 |
| _version_ | 1797556795086995456 |
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| author | Eugene A. Permyakov |
| author_facet | Eugene A. Permyakov |
| author_sort | Eugene A. Permyakov |
| collection | DOAJ |
| description | α-Lactalbumin (α-LA) is a small (Mr 14,200), acidic (pI 4–5), Ca<sup>2+</sup>-binding protein. α-LA is a regulatory component of lactose synthase enzyme system functioning in the lactating mammary gland. The protein possesses a single strong Ca<sup>2+</sup>-binding site, which can also bind Mg<sup>2+</sup>, Mn<sup>2+</sup>, Na<sup>+</sup>, K<sup>+</sup>, and some other metal cations. It contains several distinct Zn<sup>2+</sup>-binding sites. Physical properties of α-LA strongly depend on the occupation of its metal binding sites by metal ions. In the absence of bound metal ions, α-LA is in the molten globule-like state. The binding of metal ions, and especially of Ca<sup>2+</sup>, increases stability of α-LA against the action of heat, various denaturing agents and proteases, while the binding of Zn<sup>2+</sup> to the Ca<sup>2+</sup>-loaded protein decreases its stability and causes its aggregation. At pH 2, the protein is in the classical molten globule state. α-LA can associate with membranes at neutral or slightly acidic pH at physiological temperatures. Depending on external conditions, α-LA can form amyloid fibrils, amorphous aggregates, nanoparticles, and nanotubes. Some of these aggregated states of α-LA can be used in practical applications such as drug delivery to tissues and organs. α-LA and some of its fragments possess bactericidal and antiviral activities. Complexes of partially unfolded α-LA with oleic acid are cytotoxic to various tumor and bacterial cells. α-LA in the cytotoxic complexes plays a role of a delivery carrier of cytotoxic fatty acid molecules into tumor and bacterial cells across the cell membrane. Perhaps in the future the complexes of α-LA with oleic acid will be used for development of new anti-cancer drugs. |
| first_indexed | 2024-03-10T17:08:01Z |
| format | Article |
| id | doaj.art-96ce4f81082b47cf816786c489751bfe |
| institution | Directory Open Access Journal |
| issn | 2218-273X |
| language | English |
| last_indexed | 2024-03-10T17:08:01Z |
| publishDate | 2020-08-01 |
| publisher | MDPI AG |
| record_format | Article |
| series | Biomolecules |
| spelling | doaj.art-96ce4f81082b47cf816786c489751bfe2023-11-20T10:45:37ZengMDPI AGBiomolecules2218-273X2020-08-01109121010.3390/biom10091210α-Lactalbumin, Amazing Calcium-Binding ProteinEugene A. Permyakov0Institute for Biological Instrumentation of the Russian Academy of Sciences, Federal Research Center Pushchino Scientific Center for Biological Research of the Russian Academy of Sciences, 142290 Pushchino, Moscow Region, Russiaα-Lactalbumin (α-LA) is a small (Mr 14,200), acidic (pI 4–5), Ca<sup>2+</sup>-binding protein. α-LA is a regulatory component of lactose synthase enzyme system functioning in the lactating mammary gland. The protein possesses a single strong Ca<sup>2+</sup>-binding site, which can also bind Mg<sup>2+</sup>, Mn<sup>2+</sup>, Na<sup>+</sup>, K<sup>+</sup>, and some other metal cations. It contains several distinct Zn<sup>2+</sup>-binding sites. Physical properties of α-LA strongly depend on the occupation of its metal binding sites by metal ions. In the absence of bound metal ions, α-LA is in the molten globule-like state. The binding of metal ions, and especially of Ca<sup>2+</sup>, increases stability of α-LA against the action of heat, various denaturing agents and proteases, while the binding of Zn<sup>2+</sup> to the Ca<sup>2+</sup>-loaded protein decreases its stability and causes its aggregation. At pH 2, the protein is in the classical molten globule state. α-LA can associate with membranes at neutral or slightly acidic pH at physiological temperatures. Depending on external conditions, α-LA can form amyloid fibrils, amorphous aggregates, nanoparticles, and nanotubes. Some of these aggregated states of α-LA can be used in practical applications such as drug delivery to tissues and organs. α-LA and some of its fragments possess bactericidal and antiviral activities. Complexes of partially unfolded α-LA with oleic acid are cytotoxic to various tumor and bacterial cells. α-LA in the cytotoxic complexes plays a role of a delivery carrier of cytotoxic fatty acid molecules into tumor and bacterial cells across the cell membrane. Perhaps in the future the complexes of α-LA with oleic acid will be used for development of new anti-cancer drugs.https://www.mdpi.com/2218-273X/10/9/1210α-lactalbuminstructuremetal bindingfoldingunfoldingmolten globule |
| spellingShingle | Eugene A. Permyakov α-Lactalbumin, Amazing Calcium-Binding Protein Biomolecules α-lactalbumin structure metal binding folding unfolding molten globule |
| title | α-Lactalbumin, Amazing Calcium-Binding Protein |
| title_full | α-Lactalbumin, Amazing Calcium-Binding Protein |
| title_fullStr | α-Lactalbumin, Amazing Calcium-Binding Protein |
| title_full_unstemmed | α-Lactalbumin, Amazing Calcium-Binding Protein |
| title_short | α-Lactalbumin, Amazing Calcium-Binding Protein |
| title_sort | α lactalbumin amazing calcium binding protein |
| topic | α-lactalbumin structure metal binding folding unfolding molten globule |
| url | https://www.mdpi.com/2218-273X/10/9/1210 |
| work_keys_str_mv | AT eugeneapermyakov alactalbuminamazingcalciumbindingprotein |