ApoE Lipidation in Alzheimer's Disease

September 17, 2009 at 6:30 pm #11813

Participant

Hello all,
I am preparing for my qual, and our qual requires to have a topic not related to my dissertation topic. My qual topic is "Effect of lipidation of ApoE on A beta clearance in Alzheimer’s disease".
My one problem is, I’ve never worked with protein, and I tried looking up some stuff but just couldn’t find the right answer.

Question: Lipidation is a covalent modification of a protein. When ApoE is lipidated, it forms a HDL-like structure – a ball of lipids and apo proteins. I believe not all lipids will be covalently binding to the apo proteins, but then 1) how are the lipids recruited and what part of the phospholipid head can it bind to what amino acid? 2) Are only some of the lipids covalently linked to ApoE?

My qual is next week, and I am having a hard time with some basic knowledge. Please help!
Thanks!

September 19, 2009 at 3:14 pm #92885

MrMistery

Participant

well are you sure it is phospholipids that are bound to your protein? Cause from what i know it is usually fatty acids or farnesyl pyrosphosphate that is attached to proteins. in the case of attached fatty acids i am pretty sure the bond is an ester bond. in the case of farnesyl pyrophosphate i am guessing the resulting bond is also an ester bond, and that the pyrosphate is hydrolyzed in the process (although i haven’t actually read this anywhere, it makes sense).

However, for specific lipids attached to ApoE, you have to hit the library (or more modern, the pubmed)

September 21, 2009 at 8:07 pm #92929

JackBean

Participant

in the case of farnesyl (not FPP!) its ether bond 😉
In some cases, it can be bound through thiol group of cystein (but maybe only the geranyl?)

But back to the question, I think also phospholipids can bind to proteins through the phosphote.
Anyway, definitely not all lipids/fatty acids/isoprenoids will be bound covalently, most will just be sticked by the nonpolar part

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