Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
7585637 | Food Chemistry | 2018 | 7 Pages |
Abstract
This study was aimed to determine the effect of phosphorylation/dephosphorylation regulated by protein kinase A (PKA) and alkaline phosphatase (AP) on μ-calpain activity at different Ca2+ concentrations. μ-Calpain was treated with AP or PKA at 0.01, 0.05, 0.1 and 1â¯mM Ca2+. The pH value decreased in the AP group but remained stable in the control and PKA groups during incubation. Except samples incubated at 0.01 and 0.1â¯mM Ca2+ for more than 20â¯min, μ-calpain incubated with PKA showed a higher degree of autolysis than control, but lower than the AP group. The content of α-helix structure of μ-calpain increased as phosphorylation level rose. Phosphorylation of μ-calpain at serine 255, 256, 476, 417 and 420 was identified. PKA catalyzed μ-calpain phosphorylation at serine 255, 256 and 476, located at domains II and III, positively regulated μ-calpain activity. These data demonstrated that dephosphorylation and PKA phosphorylation positively regulated μ-calpain activity, which was limited by increased Ca2+ concentration.
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Authors
Manting Du, Xin Li, Zheng Li, Qingwu Shen, Ying Wang, Guixia Li, Dequan Zhang,