Apoprotein associated with LDL:

Ans. b (B-100). (Ref. Harper Biochemistry 27th ed. table. 26-1)A-l--Activates LCAT., B-100--Binds to LDL receptor and mediates VLDL secretion., C-II--Cofactor for lipoprotein lipase., B-48--Mediates chylomicron secretion., and E--Mediates Extra (remnant) uptake.ApolipoproteinsApo-AI, A-l 1, A-IVfound in HDL and chylomicronsApo-AI, All, AIVfound primarily on HDLApo-AI and Allsynthesized in liver and intestineApo-A IVsynthesized in intestine only.Apo-AIcomprises 70-80% protein of HDL All: is second most abundant in HDLApo-AILCAT activator and inversely related to CHDB-100mainly with LDLB-48mainly with chylomicron.Composition of the Lipoproteins in Plasma of Humans.LIPOPROTEINSourceMAJOR LIPIDELECTROPHO- RETIC MOBILITYMAJOR APOPRO- TEINSPROTEIN CONTENTApoli- poproteins1. ChylomicronIntestineTriglyceride (no mobility)NoneB-48, A-I, IV--A-I, A-II, A- IV,1 B-48, C-I, C-II, C-III, E2. VLDLLiver (intestine)TriglyceridePre-BetaB-100,E,--B-100, C-I, C-II, C-III3. IDLVLDLTriglyceride and cholesteryl estersBetaB-100, E--B-100, E4. LDLVLDLCholesteryl estersBetaB-100--B-1005. HDLLiver, intestine, VLDL,chylomicronsPhospholipids and CholesterolAlphaA-l, IIHighestA-I, A-II, A-IV, C-I, C-II, C-III, D,2 E