Brown and Goldstein won a Nobel Prize for their identification of the LDL-receptor in 1985. Structure of LDL-receptor is known partially with high resolution however LDL structure was until now not clearly known. So far only guessed-model have used to understand the structure of LDL at human body temperature (37 oC). Until now only low resolution structures of LDLs (25 -28 Å) at lower temperature (lower than 6 oC) have been obtained using cryo-EM and X-ray crystallographic techniques. Using the latest tools and methods in the field of cryo-electron microscopy, researchers in Finland obtained 16Angstrom resolution-structure of LDL at 37oC. It is the highest resolution obtained so far for LDL particle and that too in native hydrated state.

http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0018841

In order to gain insight researchers tried to resolve over-all folding of apoB-100 around LDL at 37oC and 6 oC . The reconstruction of LDL at 37C combined with previous indirect studies helped in resolving the folding of apoB-100 around LDL. Further confirmation was done with the help of 6 oC LDL structure and other previously published low-resolution structure of LDL bound with LDL-receptor at 4oC. The LDL structure at lower temperature (6 oC) published by them has more details than any previously published structures of LDL. They followed the approach of using pure LDL particles rather than LDL particle bound with any antibody as they argue that heterogeneity both other flxible particle could reduce the resolution during 3D reconstruction. Their approach of filtering the images sound sofisticated. Their model has finally answered all the question related to overall folding of apoB-100 protein in LDL. However the local secondary structure changes in apoB-100 caused some heterogeneity, which the researchers tried to map using boot-strap approach. The authors hint that these secondary structure changes affect the binding of LDL to LDL-receptor causing greatest menace for human being, i.e initiation of artherosclerosis. it also partially support the claim by some researcher that artherosclerosis is a protein folding problem.