(FINAL) CC1 LEC L1.4 Plasma Proteins

Prealbumin

Indicator of nutrition; binds thyroid hormones and retinol-binding protein

Albumin

Binds bilirubin, steroids, fatty acids; major contributor to oncotic pressure

Alpha-1-Antitrypsin

α1-Globulins

• __________: Acute-phase reactant;protease inhibitor

Alpha-1-Fetoprotein

α1-Globulins

• __________: Principal fetal protein; elevated levels indicate risk for spina bifida

Alpha-1-Acid glycoprotein (orosomucoid)

α1-Globulins

• __________: Acute-phase reactant; transport of drugs and hormones

Alpha-1-Lipoprotein

α1-Globulins

• __________: Lipid transport (HDL)

Alpha-1-Antichymotrypsin, Inter-alpha-trypsin inhibitor

α1-Globulins

• __________: Inhibits serine proteinases

Gc-globulin

α1-Globulins

• __________: Transports vitamin D and binds actin

Haptoglobin Type 1-1

α2-Globulins

• __________: Acute-phase reactant

Haptoglobin Type 2-1, Haptoglobin Type 2-2

α2-Globulins

• __________: Binds hemoglobin

Ceruloplasmin

α2-Globulins

• __________:Acute-phase reactant, oxidase activity; contains copper

Alpha-2-Macroglobulin

α2-Globulins

• __________: Inhibits proteases

Pre-beta lipoprotein

β-Globulins

• __________: Transports lipids (primarily VLDL triglyceride)

Transferrin

β-Globulins

• __________: Transports iron

Hemopexin

β-Globulins

• __________: Binds and transports heme

Beta-Lipoprotein

β-Globulins

• __________: Transports lipids (primarily LDL cholesterol)

Beta-2-Microglobulin (B2M)

β-Globulins

• __________: Component of human leukocyte antigens (HLA)

C4 complement, C3 complement, C1q complement

β-Globulins

• __________: Immune response

Fibrinogen

β-Globulins

• __________: Precursor of fibrin clot

C-Reactive Protein

β-Globulins

• __________: Acute-phase reactant; promotes phagocytosis

Immunoglobulin G (IgG)

γ-Globulins

• __________: Most abundant; provides long-term immunity and can cross the placenta.

Immunoglobulin A (IgA)

γ-Globulins

• __________: Primary antibody in secretions (saliva, tears, breast milk) for mucosal immunity.

Immunoglobulin M (IgM)

γ-Globulins

• __________: Largest antibody (pentamer); the first produced during a primary immune response.

Immunoglobulin D (IgD)

γ-Globulins

• __________: Functions mainly as a receptor on the surface of B-cells.

Immunoglobulin E (IgE)

γ-Globulins

• __________: Mediates allergic reactions and provides defense against parasitic infections.

Myoglobin

• Oxygen carrier in muscles

• Cardiac marker (AMI)

• ↑ = 2-3 hrs of onset, peak at 8-12 hours; returns to baseline within 18–24 hours because it is rapidly cleared by the kidneys.

Troponin (cTn)

• Cardiac marker for acute coronary syndrome

Fetal fibronectin (fFN)

• Cellular interaction

• Placental adherence to the uterus

• ↑ = Preterm labor and delivery

Cross-Linked C-Telopeptides

• Proteolytic fragment of collagen I

• Marker of bone resorption

Beta-Trace Protein

• Syn: Prostaglandin D synthase

• Marker for CSF leakage

Cystatin C

• Cysteine proteinase inhibitor

• Marker for kidney function (GFR)

Amyloid

• Fibrous protein aggregates formed from alteration of β pleated sheats

• ↑ = Amyloidoses