TY - JOUR
T1 - Oligomerization of Cu,Zn-superoxide dismutase (SOD1) by Docosahexaenoic acid and its hydroperoxides in vitro
T2 - Aggregation dependence on fatty acid unsaturation and thiols
AU - Appolinário, Patricia Postilione
AU - Medinas, Danilo Bilches
AU - Chaves-Filho, Adriano B.
AU - Genaro-Mattos, Thiago C.
AU - Cussiol, José Renato Rosa
AU - Netto, Luis Eduardo Soares
AU - Augusto, Ohara
AU - Miyamoto, Sayuri
PY - 2015/4/1
Y1 - 2015/4/1
N2 - Docosahexaenoic acid (C22:6, n-3, DHA) is a polyunsaturated fatty acid highly enriched in the brain. This fatty acid can be easily oxidized yielding hydroperoxides as primary products. Cu, Zn-Superoxide dismutase (SOD1) aggregation is a common hallmark of Amyotrophic Lateral Sclerosis (ALS) and the molecular mechanisms behind their formation are not completely understood. Here we investigated the effect of DHA and its hydroperoxides (DHAOOH) on human SOD1 oligomerization in vitro. DHA induced the formation of highmolecularweight (HMW) SOD1 species (>700 kDa). Aggregation was dependent on free thiols and occurred primarily with the protein in its apo-form. SOD1 incubation with DHA was accompanied by changes in protein structure leading to exposure of protein hydrophobic patches and formation of non-amyloid aggregates. Site-directed mutagenesis studies demonstrated that Cys 6 and Cys 111 in wild-type and Cys 6 in ALS-linked G93A mutant are required for aggregation. In contrast, DHAOOH did not induce HMW species formation but promoted abnormal covalent dimerization of apo-SOD1 that was resistant to SDS and thiol reductants. Overall, our data demonstrate that DHA and DHAOOH induce distinct types of apo-SOD1 oligomerization leading to the formation of HMW and low-molecularweight species, respectively.
AB - Docosahexaenoic acid (C22:6, n-3, DHA) is a polyunsaturated fatty acid highly enriched in the brain. This fatty acid can be easily oxidized yielding hydroperoxides as primary products. Cu, Zn-Superoxide dismutase (SOD1) aggregation is a common hallmark of Amyotrophic Lateral Sclerosis (ALS) and the molecular mechanisms behind their formation are not completely understood. Here we investigated the effect of DHA and its hydroperoxides (DHAOOH) on human SOD1 oligomerization in vitro. DHA induced the formation of highmolecularweight (HMW) SOD1 species (>700 kDa). Aggregation was dependent on free thiols and occurred primarily with the protein in its apo-form. SOD1 incubation with DHA was accompanied by changes in protein structure leading to exposure of protein hydrophobic patches and formation of non-amyloid aggregates. Site-directed mutagenesis studies demonstrated that Cys 6 and Cys 111 in wild-type and Cys 6 in ALS-linked G93A mutant are required for aggregation. In contrast, DHAOOH did not induce HMW species formation but promoted abnormal covalent dimerization of apo-SOD1 that was resistant to SDS and thiol reductants. Overall, our data demonstrate that DHA and DHAOOH induce distinct types of apo-SOD1 oligomerization leading to the formation of HMW and low-molecularweight species, respectively.
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U2 - 10.1371/journal.pone.0125146
DO - 10.1371/journal.pone.0125146
M3 - Article
C2 - 25928076
AN - SCOPUS:84957836852
VL - 10
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 4
M1 - e0125146
ER -