1. Novel enzymatic method for assaying Lp-PLA 2 in serum
- Author
-
Shigeru Ueda, Yuzo Kayamori, Daisuke Sugimori, Ken Karasawa, Shin Ichi Sakasegawa, Saki Yamaura, and Emisa Koguma
- Subjects
0301 basic medicine ,chemistry.chemical_classification ,Chromatography ,biology ,Phospholipase D ,Chemistry ,Lysophospholipase D ,Biochemistry (medical) ,Clinical Biochemistry ,Cardiovascular risk factors ,Substrate (chemistry) ,General Medicine ,Choline oxidase ,030204 cardiovascular system & hematology ,Biochemistry ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,Phospholipase A2 ,Enzyme ,biology.protein ,Choline ,lipids (amino acids, peptides, and proteins) - Abstract
Background Measurement of lipoprotein-associated phospholipase A2 (Lp-PLA2) can be used as an adjunct to traditional cardiovascular risk factors for identifying individuals at higher risk of cardiovascular events. This can be performed by quantification of the protein concentration using an ELISA platform or by measuring Lp-PLA2 activity using platelet-activating factor (PAF) analog as substrate. Here, an enzymatic Lp-PLA2 activity assay method using 1-O-Hexadecyl-2-acetyl-rac-glycero-3-phosphocholine (rac C16 PAF) was developed. Methods The newly revealed substrate specificity of lysoplasmalogen-specific phospholipase D (lysophospholipase D (LysoPLD)) was exploited. Lp-PLA2 hydrolyzes 1-O-Hexadecyl-2-acetyl-sn-glycero-3-phosphocholine (C16 PAF) to 1-O-Hexadecyl-2-hydroxy-sn-glycero-3-phosphocholine (LysoPAF). LysoPLD acted on LysoPAF, and the hydrolytically released choline was detected by choline oxidase. Results Regression analysis of Lp-PLA2 activity measured by the enzymatic Lp-PLA2 activity assay vs. two chemical Lp-PLA2 activity assays, i.e. LpPLA2 FS and PLAC® test, and ELISA, gave the following correlation coefficients: 0.990, 0.893 and 0.785, respectively (n = 30). Conclusion Advantages of this enzymatic Lp-PLA2 activity assay compared with chemical Lp-PLA2 methods include the following; (i) only requires two reagents enabling a simple two-point linear calibration method with one calibrator (ii) no need for inhibitors of esterase-like activity in serum.
- Published
- 2018
- Full Text
- View/download PDF