Dataset Information

?-Lactalbumin, Amazing Calcium-Binding Protein.

ABSTRACT: ?-Lactalbumin (?-LA) is a small (Mr 14,200), acidic (pI 4-5), Ca2+-binding protein. ?-LA is a regulatory component of lactose synthase enzyme system functioning in the lactating mammary gland. The protein possesses a single strong Ca2+-binding site, which can also bind Mg2+, Mn2+, Na+, K+, and some other metal cations. It contains several distinct Zn2+-binding sites. Physical properties of ?-LA strongly depend on the occupation of its metal binding sites by metal ions. In the absence of bound metal ions, ?-LA is in the molten globule-like state. The binding of metal ions, and especially of Ca2+, increases stability of ?-LA against the action of heat, various denaturing agents and proteases, while the binding of Zn2+ to the Ca2+-loaded protein decreases its stability and causes its aggregation. At pH 2, the protein is in the classical molten globule state. ?-LA can associate with membranes at neutral or slightly acidic pH at physiological temperatures. Depending on external conditions, ?-LA can form amyloid fibrils, amorphous aggregates, nanoparticles, and nanotubes. Some of these aggregated states of ?-LA can be used in practical applications such as drug delivery to tissues and organs. ?-LA and some of its fragments possess bactericidal and antiviral activities. Complexes of partially unfolded ?-LA with oleic acid are cytotoxic to various tumor and bacterial cells. ?-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 ?-LA with oleic acid will be used for development of new anti-cancer drugs.

SUBMITTER: Permyakov EA

PROVIDER: S-EPMC7565966 | biostudies-literature | 2020 Aug

REPOSITORIES: biostudies-literature

ACCESS DATA

Publications

α-Lactalbumin, Amazing Calcium-Binding Protein.

Permyakov Eugene A EA

Biomolecules 20200820 9

α-Lactalbumin (α-LA) is a small (Mr 14,200), acidic (pI 4-5), Ca2+-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 Ca2+-binding site, which can also bind Mg2+, Mn2+, Na+, K+, and some other metal cations. It contains several distinct Zn2+-binding sites. Physical properties of α-LA strongly depend on the oc ...[more]

PMID: 32825311

Similar Datasets

Project description:PURPOSE: Pterygium is an ocular surface disease of unknown etiology associated with epithelial and fibrovascular outgrowth from the conjunctiva onto the cornea. S100 proteins are calcium-activated signaling proteins that interact with other proteins to modulate biological functions such as cell migration, proliferation, and differentiation. The aim of this study was to investigate the presence of various S100 proteins in pterygium compared to normal conjunctiva. METHODS: Immunofluorescent staining using antibodies against S100A4, S100A6, S100A8, S100A9, and S100A11 were conducted to investigate the expression and tissue distribution. S100 protein secretions and expressions were confirmed using western blot and quantitative real-time polymerase chain reaction (RT-PCR), respectively. RESULTS: Immunofluorescent staining demonstrated the presence of S100A4, S100A6, S100A8, S100A8, S100A9, and S100A11 in both conjunctival and pterygial epithelium. No significant difference was found in the localization and expression of S100A4. In both conjunctiva and pterygium, S100A4-positive cells were found in superficial and suprabasal layers. S100A6 expression was strong in the superficial layer of pterygium epithelium but relatively weaker in the suprabasal and superficial cells of normal conjunctiva epithelium. S100A8 and S100A9 were localized in the superficial layer of both pterygium and normal conjunctiva epithelium, with higher levels in pterygium than uninvolved conjunctiva. S100A11 was expressed in the basal cells of conjunctival epithelium but in the suprabasal layers of pterygium epithelium. Western blot and RT-PCR confirmed the presence of S100A4, S100A6, S100A8, S100A9, and S100A11 in pterygium and conjunctiva tissue. CONCLUSIONS: Higher levels of S100A6, S100A8, and S100A9 expressions were detected in the pterygium tissue relative to normal conjunctiva. In addition, a distinct alteration of localization of S100A11 expression was observed in pterygium epithelium compared to the conjunctiva. Therefore, these S100 proteins may be associated with the formation of pterygium.

Dataset Information

?-Lactalbumin, Amazing Calcium-Binding Protein.

Publications

α-Lactalbumin, Amazing Calcium-Binding Protein.

Similar Datasets

OmicsDI is part of the ELIXIR infrastructure