AffinityImmuno Products

Introduction

ANGPTL3 is a liver-secreted member of the angiopoietin-like protein family that circulates as an intact molecule and as separately cleaved fragments, each with distinct roles. Its N-terminal segment restrains the breakdown of circulating triglycerides by blocking lipoprotein lipase and endothelial lipase, thereby shaping plasma levels of LDL, HDL, and triglycerides, while the C-terminal fibrinogen-like portion engages integrin receptors on vascular endothelium to influence cell adhesion and vessel growth. Loss-of-function variants in the ANGPTL3 gene produce familial hypobetalipoproteinemia type 2, a condition marked by unusually low circulating lipid levels and impaired fat absorption. Because of this lipid-regulating activity, ANGPTL3 has drawn attention as a target for therapies aimed at lowering cardiovascular risk, and quantitative immunoassays are used to track circulating protein levels in research settings.

ANGPTL3 has become a validated cardiovascular drug target since the FDA approval of evinacumab for homozygous familial hypercholesterolemia, and quantitative ANGPTL3 immunoassays are used in research tracking lipid-lowering therapy response as well as studying the rare loss-of-function condition familial hypobetalipoproteinemia type 2.

Principle of the Assay

This kit uses a sandwich enzyme immunoassay format in which the microtiter plate wells are pre-coated with a capture antibody specific to Human ANGPTL3. Standards or samples are added to the appropriate wells together with a biotin-conjugated detection antibody that also recognizes Human ANGPTL3. Avidin conjugated to horseradish peroxidase (HRP) is then added to each well and allowed to incubate, linking enzymatic activity to any captured analyte. Upon addition of TMB substrate solution, a colorimetric signal develops exclusively in wells containing Human ANGPTL3, the biotin-conjugated antibody, and the avidin-HRP conjugate. The enzymatic reaction is stopped by the addition of a sulphuric acid stop solution, and absorbance is measured spectrophotometrically at 450 nm (± 10 nm). Human ANGPTL3 concentrations in the samples are determined by comparing sample optical density values against a standard curve.