Effects of phosphorylation on μ-calpain activity at different incubation temperature. (October 2017)

• Record Type: Journal Article
• Authors: Du, Manting; Li, Xin; Li, Zheng; Shen, Qingwu; Wang, Ying; Li, Guixia; Zhang, Dequan
• Is Part Of: Food research international. Volume 100 Part 2(2017)
• Page Start: 318
• Page End: 324
• Publication Date: 2017-10
• Subjects: μ-Calpain -- Protein kinase A -- Alkaline phosphatase -- Phosphorylation -- Temperature; Food -- Analysis -- Periodicals; Food industry and trade -- Periodicals; Food industry and trade -- Canada -- Periodicals; Food Technology -- Periodicals; Food -- Periodicals; Food-Processing Industry -- Periodicals; Aliments -- Industrie et commerce -- Périodiques; Aliments -- Industrie et commerce -- Canada -- Périodiques; Aliments -- Recherche -- Périodiques; Food industry and trade; Canada; Periodicals; Electronic journals; 664.005
• DOI: 10.1016/j.foodres.2017.08.055
• Languages: English
• ISSNs: 0963-9969

Abstract

Abstract: The study investigated the effects of alkaline phosphatase (AP) dephosphorylation and protein kinase A (PKA) phosphorylation on μ-calpain activity and its sensitivity to temperature. The purified μ-calpain was treated with AP or PKA for 30 min at 30 °C to modulate its phosphorylation level. Samples were then incubated at controlled freezing point (− 1), 4, 25 and 37 °C, respectively. The results showed that PKA and AP had no influence on pH values of incubation solution. At − 1 and 4 °C, the degradation rate of μ-calpain was maximum in AP group and minimum in control group. Low temperature of controlled freezing point prevented dephosphorylation and phosphorylation progression and delayed μ-calpain degradation. Increased incubation temperature of 4, 25 and 37 °C increased μ-calpain degradation. Two about 50 kDa degradation products from μ-calpain were identified, of which the intensity was also lower in control group than in the other two groups. These observations demonstrated that AP dephosphorylation and PKA phosphorylation of μ-calpain promoted μ-calpain autolysis and activation. Graphical abstract: Highlights: Dephosphorylation of μ-calpain promoted its autolysis and activation. PKA phosphorylation of μ-calpain also increased μ-calpain activity. Two about 50 kDa degradation products from μ-calpain were identified. Controlled freezing point prevented dephosphorylation and phosphorylation process. Higher temperature shrinks the effects caused by phosphorylation.