Key Laboratory of Bioactive Substances and Resources Utilization of Chinese Herbal Medicine, Ministry of Education, Institute of Medicinal Plant Development, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100193, China.
School of Environment and Life Science, Kaili University, Kaili 556011, China.
Molecules. 2019 Jul 30;24(15):2765. doi: 10.3390/molecules24152765.
NCMN (-(3-carboxy propyl)-4-methoxy-1,8-naphthalimide), a newly developed ratiometric two-photon fluorescent probe for human Cytochrome P450 1A (CYP1A), shows the best combination of specificity and reactivity for real-time detection of the enzymatic activities of CYP1A in complex biological systems. This study aimed to investigate the interspecies variation in NCMNdemethylation in commercially available liver microsomes from human, mouse, rat, beagle dog, minipig and cynomolgus monkey. Metabolite profiling demonstrated that NCMN could be -demethylated in liver microsomes from all species but the reaction rate varied considerably. CYP1A was the major isoform involved in NCMNdemethylation in all examined liver microsomes based on the chemical inhibition assays. Furafylline, a specific inhibitor of mammalian CYP1A, displayed differential inhibitory effects on NCMNdemethylation in all tested species. Kinetic analyses demonstrated that NCMNdemethylation in liver microsomes form rat, minipig and cynomolgus monkey followed biphasic kinetics, while in liver microsomes form human, mouse and beagle dog obeyed Michaelis-Menten kinetics, the kinetic parameters from various species are much varied, while NCMNdemethylation in MLM exhibited the highest similarity of specificity, kinetic behavior and intrinsic clearance as that in HLM. These findings will be very helpful for the rational use of NCMN as a practical tool to decipher the functions of mammalian CYP1A or to study CYP1A associated drug-drug interactions .
NCMN（（-（3-羧丙基）-4-甲氧基-1,8-萘酰亚胺），一种新开发的用于人细胞色素 P450 1A（CYP1A）的比率双光子荧光探针，在实时检测复杂生物系统中 CYP1A 的酶活性方面表现出最佳的特异性和反应性结合。本研究旨在研究商业可用的来自人、鼠、大鼠、比格犬、小型猪和食蟹猴的肝微粒体中 NCMN 的去甲基化的种间差异。代谢产物分析表明，NCMN 可以在所有物种的肝微粒体中被去甲基化，但反应速率差异很大。基于化学抑制试验，CYP1A 是所有研究的肝微粒体中参与 NCMN 去甲基化的主要同工酶。呋喃西林，一种哺乳动物 CYP1A 的特异性抑制剂，对所有测试物种的 NCMN 去甲基化显示出不同的抑制作用。动力学分析表明，大鼠、小型猪和食蟹猴肝微粒体中的 NCMN 去甲基化遵循双相动力学，而人、鼠和比格犬肝微粒体中的 NCMN 去甲基化遵循米氏动力学，来自不同物种的动力学参数差异很大，而 MLM 中的 NCMN 去甲基化在特异性、动力学行为和内在清除率方面与 HLM 最为相似。这些发现将非常有助于合理使用 NCMN 作为一种实用工具来破译哺乳动物 CYP1A 的功能或研究 CYP1A 相关的药物相互作用。
