Native human LDL protein

Supplementary information

This supplementary information is collated from multiple sources and compiled automatically.

Low-density lipoprotein often referred to as LDL or "bad cholesterol" serves as a carrier for lipids in the bloodstream. LDL particles are spherical and contain an apolipoprotein B-100 shell with a core mostly filled with cholesterol esters. It has an approximate molecular weight of 2536 kDa. LDL is mainly expressed in the liver where it is released into the circulation to deliver cholesterol to various tissues. It is an essential component that transports cholesterol and other lipids through the body for structural and metabolic functions.

Biological function summary

LDL plays an important role by supplying cholesterol to cells which is critical for membrane structure and hormone synthesis. LDL binds to specific receptors on the cell surface prompting its cellular uptake through the LDL uptake assay mechanisms including receptor-mediated endocytosis. This process involves the LDL protein engaging with a receptor complex facilitating the internalization of cholesterol for cell usage or storage. Native LDL can be distinguished from oxidized forms which have different roles in health and disease.

Pathways

LDL is vital in cholesterol homeostasis and lipid metabolism pathways. One notable pathway includes its interaction in the mevalonate pathway essential for cholesterol biosynthesis. The interaction with the insulin signaling pathway also highlights the significance of LDL in energy homeostasis. Related proteins such as high-density lipoprotein (HDL) and very low-density lipoprotein (VLDL) work in tandem with LDL forming a complex system for managing lipid transport and affecting cholesterol levels.

LDL is closely associated with atherosclerosis and cardiovascular disease. High LDL levels lead to cholesterol accumulation in arterial walls promoting the formation of plaques and increasing the risk of heart disease. Apolipoprotein B-100 part of the LDL structure is often investigated in the context of these diseases because it mediates LDL's attachment to arterial walls. Understanding LDL's relationship with these disorders highlights the importance of controlling its levels through medical and lifestyle interventions therefore minimizing disease risk.