1C1Z, 1G4F, 1G4G, 1QUB, 2KRI, 3OP8, 4JHS35011818ENSG00000091583ENSMUSG00000000049P02749Q01339NM_000042NM_013475NP_000033NP_038503β2-glycoprotein 1, also known as beta-2 glycoprotein 1 and Apolipoprotein H (Apo-H), is a 38 kDa multifunctional plasma protein that in humans is encoded by the APOH gene.

Although previously referred to as apolipoprotein H, it is not present in appreciable quantities in the lipoprotein fractions, so ApoH is therefore thought to be a misnomer.

[18] Positivity for anti-cardiolipin antibodies in diagnostic tests for autoimmune antiphospholipid syndrome requires the presence of β2-GP1in the cardiolipin extract.

[21] This protein domain is composed of four well-defined anti-parallel beta-strands and two short alpha-helices, as well as a long highly flexible loop.

[22] Additionally, the fifth protein domain appears to resemble the other four in Apolipoprotein with the exception of three internal disulfide bonds and an extra C-terminal loop.