Lipid Metabolism pathway
LDL

LDLR

CHOL

LIPCBA
SR-B1IDL
ApoER
LPLLiver

ABCG5/8
ABC11ABCB4
ABCC2VLDL
ChyloRemn

LPL

HDL

ApoE
ApoC2CETP

Chylomicron

Cells and organisms use lipoproteins to move hydrophobic lipid molecules, which are not watersoluble, through the aqueous blood and tissue lymph environment. Lipoprotein particles are definedby their complement of associated apolipoproteins (Apo) and their content of cholesterol (CHOL),
triglyceride (TG) and phospholipid that each particle carries. This protein and lipid content defines theparticles buoyant density and subdivides them into 4 major classes: high density lipoprotein (HDL),
low density lipoprotein (LDL), very low density lipoprotein (VLDL), and chylomicrons.
HDL is formed by the transfer of cholesterol and phospholipids onto apolipoproteinA-1 (ApoA-1) togenerate pre β-HDL. This process is catalyzed by the ATP-binding cassette (ABC) A1 (ABCA1)transporter, which is expressed in the peripheral tissues, intestine and liver (not shown here). The
cholesterol in the nascent pre β-HDL is then esterified by lysolecithin cholesterol acyltransferase(LCAT) as part of a process that generates mature spherical HDL. ABCG1, another ABC transporter,
is able to load more cholesterol onto mature HDL from peripheral tissues and along with ABCA1 is
important in allowing macrophages to efflux artery wall cholesterol, which prevents atherosclerotic
vessel disease. HDL cholesterol-esters are taken up by scavenger receptor BI (SRBI) in liver and afterhydrolysis the resulting free cholesterol is metabolized to bile acids (BA). The bile acids along withmore free cholesterol is excreted into the digestive tract via biliary secretion in a process that againutilizes ABC transporters (ABCG5/ABCG8, ABCB11, ABCB4 and ABCC2).
Conversely, in the small intestine absorbed dietary fatty acids are converted into triglycerides (TG) andare packaged and secreted into the bloodstream as chylomicrons, a lipoprotein particle rich in TG and
apoB-48. TG in this lipoprotein is rapidly hydrolyzed into free fatty acids by lipoprotein lipase (LPL),
leading to the formation of chylomicron remnants (Chylo Remn), which are taken up by the liver via
the apoE receptor (ApoER). Dietary cholesterol is also packaged into HDL particles by the action ofABCA1 and ABCG1, and as HDL circulates there is an increase in its apoC2 and apoE ratio becauseof a protein exchange between HDL and VLDL. Cholesterol ester from HDL is also transferred toVLDL remnant particles (IDL) by the action of cholesteryl ester transfer protein(CETP). IDL loses most of apolipoprotein except apoB and is converted
to LDL by the action of hepatic lipase (LIPC).

LCAT
ABCG1
ApoBTG

ABCG1

preβ-HDL

CHOL
NPC1

ABCG5CHOL

ABCA1ABCA1

ABCG8Intestine

PeripheralTissuesFinally, LDL is taken up by liver and other tissues in anendocytotic process that involves the LDL receptor (LDLR). In
humans mutations in the LDL receptor leads to elevatedplasma LDL levels (hypecholesterolemia), whereas
mutations in ABCA1 ablates circulating HDL (Tangierdisease). Mutations of ABCG5 or ABCG8 leads tositosterolemia, which is characterized by elevated levels ofcirculating cholesterol and dietary plant sterols. In all ofthese conditions the patients develop premature
cardiovascular disease.
Michael Fitzgerald PhD, Harvard Medical School

ApoA1

www.abcam.com
Produced in collaboration with Michael Fitzgerald PhD

Lipid Metabolism antibodies from Abcam:
ProductClonality

Applications

HostSpecies
Reactivity

ABCA1
ABCA1
ABCA1
ABCA1
ABCB4
ABCG1
ABCG1
ABCG5
ABCG8
AMPK gamma 1
Apolipoprotein A I
Apolipoprotein A I
Apolipoprotein B
Apolipoprotein B
Apolipoprotein B
Apolipoprotein B
Apolipoprotein CII
Apolipoprotein E
Apolipoprotein E
BMAL1
BMAL1
Caveolin 1
CETP
CETP
Cholesterol Oxidase
COX2 / Cyclooxygenase 2

Datasheetwww.abcam.com/ab…

M
PP
M
M
M
PPP
M
PM
PM
PP
P
M
PMPP

ELISA, ICC/IF, IHC-P, IP, WB
Fast Track - see datasheet
IHC-Fr, IHC-P, IP, WB
WB
Flow Cyt, ICC, IHC-Fr, WB
ICC, IHC-P, WB
WB
WB
WB
Flow Cyt, ICC, IHC-P, IP, WB
IP, WB, ELISA
IP, WB, ICC/IF, IHC-P
Dot, ELISA, IF, IHC-P, WB
ELISA, RIA
ID, IHC-P, WB
DID, Ie, IHC-Fr, RID, RIe
Fast Track - see datasheet
ICC/IF, IHC-P, IP, WB
Flow Cyt, IHC-P, IP, WB
Dot, WBELISA, WB
ICC/IF, WB

Mouse
RabbitRabbitRat
MouseRabbit
RabbitRabbitRabbitRabbitGoat
RabbitGoat
Mouse
RabbitSheep
Goat
RabbitRabbitMouse
RabbitRabbitHu, Ms, Chk
Hu*, Ms*, Rat*, Dog*Hu, Ms, MkMs
Hu
Hu, Ms, Rat, Cow
Ms, Hu*
Hu
Hu
Hu
Hu
Hu
Hu, RbHu
Hu, MsHu, Rat, Gpig, Pig

MPP
P

ELISA, IP, WB
WB
Conjugation, Dot, ELISA, IP, WB
ICC, IHC-P, WB

Mouse
RabbitGoat
Goat

Hu, RatHu
Hu
Hu, MsHu, Ms, Rat, Cow*,Dog*, Pig*
Hu, RbHu, Ms, Rat, Rb
Microorganisms
Hu, Ms, Rat, Shp,
Cow*, Dog*, Pig*

18180
14146
7360
48263
24108
52617
36969
45279
45280
32382
7613
52945
7616
20624
20737
8947
7618
52607
52924
53215
49421

Clonality

Applications

M
P
P
M
P
M
P
M
P
M
PM
P

IHC-Fr, IHC-P
ELISA, WB
ELISA, WB
ELISA, IHC-Fr
EIA, IP, RIA, WB
Flow Cyt, IP, WB, ICC/IF, IHC-P
ELISA, WB
WB
ELISA, IHC-P
Flow Cyt, ICC/IF, IHC-P, IP, WB
Flow Cyt, ICC, IHC-Fr, WB
WB
WB

Low Density LRP

M

18199
2726
1901234495

Low Density LRP
MRP2
PON1
Scavenging Receptor SR-BI
Scavenging Receptor SR-BI
Scavenging Receptor SR-BI
VLDL
VLDL
VLDL
VLDL Receptor

M
M
PM
M
PPM
PM

Flow Cyt, IHC-P, WB, ICC/IF,ELISA, IHC-Fr
ELISA, Flow Cyt, IHC-Fr, IP, WB
IHC-P, IP, WB, IHC-Fr, IP
ICC/IF, WB
BL, Flow Cyt, IHC-Fr
ICC, IHC-P, WB
WB
ELISA, WB
Flow Cyt, WB
ELISA, ICC/IF, WB
ELISA, WB

23672*= predicted to react

Host

RabbitRabbitChickenMouse
RabbitRabbitChicken
Mouse
RabbitRabbitRabbitMouse
Rabbit

Mouse
Mouse
Mouse
RabbitMouse
RabbitRabbitChicken
Mouse
RabbitMouse

Species
Reactivity

Datasheetwww.abcam.com/ab…

Hu, Ms, Rat
Hu, Ms, Rat
Hu
Hu
Hu
Hu
Hu
Hu
Hu
Hu, Ms, Rat
Hu, Ms, Rat
Hu
Hu, Ms, Bb*, Chmp*,
RMk*

21704
52237
15863
34788
51419
51060
15870
57471
14519
52818
30532
56493

Hu, Ms, Rb
Hu
Hu, RatHu, Ms*, Rat*
Rat
Hu, Ms, Rat
Ms, Rat
Hu
Hu
HuHu

28320
23346
3373
53193
37231
52629
24603
16419
63977
35056
62543

65364

Apolipoprotein E (ab52607)
HostMouseSpecies cross reactivity
Hu, Ms, Chk

HostRabbitSpecies cross reactivity
Hu, Ms, Rat, Cow

ABCG1 (ab52617)
Clonality Applications
M
ICC, IHC-P, WB

Product

COX2 / Cyclooxygenase 2
COX2 / Cyclooxygenase 2HDL
HDL
HDL
LCAT
LDL
LDL
LDL (Copper oxidized)
LDL Receptor
LDL Receptor
LIPG
LIPG

ABCA1 (ab18180)
Clonality Applications
M
ELISA, ICC/IF, IHC-P, IP, WB

www.abcam.com/cardiovascularClonality Applications
M
ICC/IF, IHC-P, IP, WB

HostRabbitSpecies cross reactivity
Hu, RatClonality Applications
HostM
Flow Cyt, ICC/IF, IHC-P, IP, WB RabbitSpecies cross reactivity
Hu, Ms, Rat

LDL Receptor (ab52818)