CC: Proteins

Prealbumin

Indicator of nutrition

Prealbumin

Binds thyroid hormones and retinol binding protein.

Albumin

Single most abundant protein

Albumin

Binds bilirubin, steroids, fatty acids.

Albumin

Major contributor to oncotic pressure.

1-Globulins

1-Antitrypsin

Major 1-Globulin; acute-phase reactant; a protease inhibitor

1-Fetoprotein

Principal fetal protein

Alpha fetoprotein

Marker for liver cancer

1-Acid glycoprotein (orosomucoid)

acute-phase reactant

1-Lipoprotein (HDL)

Transports lipids

1-Antichymotrypsin

Inhibits serine proteinase

Inter-1-Trypsin inhibitor

Inhibits proteinase

Gc-Globulin

Binds Vitamin D and actin

Ceruloplasmin

Peroxidase activity; contains copper

2-Macroglobulin

Largest non-immunoglobulin plasma protein.

2-Macroglobulin

Rises 10-fold in nephrotic syndrome or equal to greater than that of albumin.

2-Macroglobulin

Inhibits thrombin, trypsin, pepsin

Hemopexin

Binds heme

Lipoproteins (LDL)

Transports lipids (primarily cholesterol), migrates with a characteristic sharp leading edge and a feathery trailing edge.

Microglobulin (B2M)

Component of human leukocyte antigen (HLA) molecules class 1

Fibrinogen

Elevated in pregnancy and use of birth control pills

Fibrinogen

Precursor of fibrin clot

C-reactive protein (CRP)

acute-phase reactant; motivates phagocytosis in inflammatory disease

Prealbumin

Function:

Transport Vit. A, T4

Prealbumin

Clinical Observations:

• after relatively brief hepatocellular dysfunctions

• with widespread tissue damage

Transferrin

Function:

Transports iron

Transferrin

Clinical Obsevations:

• when Fe stores are low (except when protein malnutrition coexists)

• in pregnancy & oral contraceptive use

• with protein - losing states congenital deficiency states

Haptoglobin

Function:

Binds free hemoglobin

Haptoglobin

Clinical Observations:

• disappears when Hb escapes from RBCs (hemolysis)

• with infection, malignancy, burns

• with severe liver disease

• genetically determined structural variants are numerous

1-antitrypsin

Function:

Inhibits naturally occurring proteases

1-antitrypsin

Clinical Observations:

• genetically determined absence or diminution exists fairly frequently

• with pregnancy & oral contraceptive use

• with acute inflammatory conditions

Ceruloplasmin

Function:

Transports copper

Ceruloplasmin

Clinical Observations:

• with chronic inflammation, tissue neurosis

• with pregnancy liver disease, with protein-losing states congenital

• absent in Wilson’s disease, an uncommon genetically determined disease

Antithrombin III

Function:

Enhances antithrombin effect of heparin

Antithrombin III

Clinical Observations:

• with hepatocellular dysfunction, protein-losing states

• with pregnancy, oral contraceptive use

• genetically determined deficiency occurs in 1:2000