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Structural and biological properties of human immunoglobulins

Print of this table: Lefranc, M.-P. and Lefranc, G., The Immunoglobulin FactsBook, Academic Press, London, UK (458 pages), 2001, ISBN:012441351X

Properties

Classes and subclasses
IgM IgD IgG IgA IgE
IgG1 IgG2 IgG3 IgG4 IgA1 IgA2
Molecular weight of secreted form (kDa) (1) 950(p) 170-180 150 150 155-165 150 160 (m)
300 (d)		 160 (m)
350 (d)		 190
Chain composition (κ2μ2)5
or
(λ2μ2)5		 κ2δ2
or
λ2δ2		 κ2γ12
or
λ2γ12		 κ2γ22
or
λ2γ22		 κ2γ32
or
λ2γ32		 κ2γ42
or
λ2γ42		 (κ2α12)1-2
or
(λ2α12)1-2		 (κ2α22)1-2
or
(λ2α22)1-2		 κ2ε2
or
λ2ε2
Functional valency 5 or 10 2 2 2 or 4 2
Structure (2) monomer (mb) pentamer (s) monomer monomer monomer (mb) dimer (s) monomer
Interchain disulphide bonds per monomer 1 1 2 4 11 2 2 1
Other chain J chain
(16 kDa)		 - - J chain (16 kDa) SC secretory component (70 kDa) -
Sedimentation coefficient in Svedberg unit (S) 18-20 7 6.5-7.0 7, 10, 13, 15, 17 7.9
Carbohydrate average (%) 10-12 9-14 2-3 7-11 12-13
Adult level range (age 16-60) in serum (g/L) (3) 0.25-3.1 0.03-0.4 5-12 2-6 0.5-1 0.2-1 1.4-4.2 0.2-0.5 0.0001-0.0002
8.0-16.8
Approximate % total IG in adult serum 10 0.2 45-53 11-15 0.03-0.06 0.015-0.045 11-14 1-4 0.004
Synthetic rate (mg/kg Weight/day) 3.3 0.2 33 33 33 33 19-29 3.3-5.3 0.002
Biological half-life (day) 5-10 0.4 21-24 21-24 7-8 21-24 5-7 4-6 1-5
Transplacental transfer 0 2-8 ++ + ++ ++ 0 0 0
Complement activation classical pathway (C1q) +++ 0 +++ + +++ 0 0 0 0
Complement activation alternative pathway 0 0 0 0 0 0 + 0 0
Binding macrophages and other phagocytic cells (FcγR or FCGR) (4) 0 + +++ +/- +++ +/- 0 0 0
Binding to mast cells and basophils (FcεR or FCER) 0 0 0 0 0 0 0 0 +++
Binding to epithelial poly-IG receptor + 0 0 0 0 0 +++ +++ 0
Reactivity with Staphyloccus protein A 0 0 ++ ++ 0 ++ 0 0 0
Notes:
(1) approximate molecular weight (m=monomer, d=dimer, p=pentamer)
(2) mb=membrane, s=secreted
(3) total IG Adult level range (age 16-60) in serum: 7.5-21.7 g/L
(4) +/- : binding depends on the FCGR isotype and on the cell type