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Structural and biological properties of human immunoglobulins


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

2. Human immunoglobulin (IG) chain characteristics

3. IG interchain disulfide bridges per monomer

4. Lysines and cysteines of the Homo sapiens IGHG1, IGKC and IGLC1 and positions in the C-DOMAIN

5. Amino acid positions involved in ADCC, ADCP, CDC, half-life and half-IG exchange

6. IMGT engineered variant nomenclature: IGHG variants

7. Homo sapiens IGHG1 amino acids involved in the interactions with the C1q, FcγR and FCGRT

Properties Human IG 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 (nb of antigen binding sites) 5 or 10 2 2 2 or 4 2
Structure (2) monomer (mb) pentamer (s) monomer (mb, s) monomer (mb, s) monomer (mb, s) dimer (sec) monomer (mb, s)
Inter-heavy (H-H) disulfide bridges per monomer (positions) 1 1 2 4 11 2 2 1
Other chain J chain
(16 kDa)		 - - J chain (16 kDa), 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
(% of the subclass in the class)		 10 0.2 45-53
(70-80)		 11-15
(18-23)		 3-6
(6-8)		 1-4
(2-6)		 11-14
(90)		 1-4
(10)		 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 2-8 21-24 21-24 7-8 21-24 5-7 4-6 1-5
Transplacental transfer 0 0 ++ + ++ ++ 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)a ++ 0 0 0
Notes:
a IgG3 allotype dependent
(1) Approximate molecular weight (m=monomer, d=dimer, p=pentamer)
(2) mb=membrane, s=secreted, sec=secretory (see The Immunoglobulin FactsBook). Human immunoglobulin chain characteristics (here)
(3) Total IG adult level range (age 16-60) in serum: 9.5-21.7 g/L
(4) +/- : binding depends on the FCGR isotype and on the cell type (see The Immunoglobulin FactsBook)

Schematic representation of the 5 IG classes and subclasses


Membrane IG are shown. Click on the links for representation of secreted IG


IgM IgD IgG1 IgA1 IgE
Pentameric IgM 4 IgG subclasses 2 IgA subclasses
Monomeric and dimeric IgA

IG representation

See also:

Created:
18/05/2004
Last updated:
22/09/2023
Authors:
Souphatta Sasorith, Valérie Thouvenin and Marie-Paule Lefranc
Editor:
Chantal Ginestoux