Chylomicrons and LCAT

[justadream]

---

Members don't see this ad.

Chylomicrons contain the apolipoprotein A-I which activates LCAT (an enzyme that catalyzes the esterification of cholesterol).

Why do chylomicrons have LCAT?

I understand that while chylomicrons primarily contain TG, they also contain cholesterol. Is the LCAT used to make the cholesterol into a cholesterol-ester so that it can be transported in the chylomicron?

In other words, is the cholesterol contained in a chylomicron in the form of a cholesterol-ester?

 

[gettheleadout]

Most of the cholesterol content of chylomicrons is esterified, not free cholesterol, but I think you're extrapolating too far based on chylomicrons containing apoA-I. Dietary free cholesterol is esterified in the enterocytes by acyl-CoA:cholesterol acyltransferases, yielding cholesteryl esters for incorporation into the cores of chylomicrons. Also, apoA-I does a lot more than just activate plasma LCAT, that just happens to be the highest-yield function so FA boils it down to that.

For further reading see: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3243485/