Kanta Poonam, Ghosh Tulikalipi, Kaur Anit, Muthukumarappa Thungapathra
Department of Biochemistry, Postgraduate Institute of Medical Education and Research Chandigarh 160012, India.
Int J Biochem Mol Biol. 2021 Feb 15;12(1):1-7. eCollection 2021.
Alkaline phosphatase is an enzyme that converts para-nitrophenyl phosphate to para-nitrophenol (yellow coloured) in 2-amino, 2-methyl, 1-propanol buffer at pH 10.5. However, when this protocol is applied to the in vitro cellular model systems to estimate alkaline phosphatase activity, it tends to generate clumps of genomic DNA, leading to inaccurate pipetting for protein estimation. The aim of the study was to introduce minor modifications in the existing protocol to make it simple, cost-effective, with minimal labor-intensive procedures while estimating alkaline phosphatase activity in cellular model systems. The genomic DNA clumps were dissolved by depurination (adding 0.2 N HCl) and fragmentation (adding 0.2 N NaOH) during enzyme estimation. Moreover, these minor modifications have been standardized and optimized extensively by using serum samples (rich source of alkaline phosphatase), hFOB/ER9 (human Fetal osteoblastic cell) and HepG2 cells. Our results suggest that the modification incorporated in previously published method was robust enough to estimate ALP activity and protein concentration accurately. There was no significant variation in ALP activity estimated after modification (P > 0.05). This innovative approach could be beneficial for a researcher by providing an easy, cost effective and less labor-intensive solution for estimation of enzymatic activity in cellular model systems.
碱性磷酸酶是一种在pH 10.5的2-氨基-2-甲基-1-丙醇缓冲液中,将对硝基苯磷酸酯转化为对硝基苯酚(呈黄色)的酶。然而,当将此方案应用于体外细胞模型系统以评估碱性磷酸酶活性时,它往往会产生基因组DNA团块,导致在蛋白质评估中移液不准确。本研究的目的是对现有方案进行微小修改,使其在评估细胞模型系统中的碱性磷酸酶活性时简单、经济高效,且劳动强度最小。在酶活性评估过程中,通过脱嘌呤(加入0.2N HCl)和片段化(加入0.2N NaOH)来溶解基因组DNA团块。此外,通过使用血清样本(碱性磷酸酶的丰富来源)、hFOB/ER9(人胎儿成骨细胞)和HepG2细胞,对这些微小修改进行了广泛的标准化和优化。我们的结果表明,对先前发表方法所做的修改足够可靠,能够准确评估碱性磷酸酶活性和蛋白质浓度。修改后评估的碱性磷酸酶活性没有显著差异(P>0.05)。这种创新方法可为研究人员提供一种简单、经济高效且劳动强度较小的解决方案,用于评估细胞模型系统中的酶活性。