To improve security and privacy, we are moving our web pages and services from HTTP to HTTPS. To give users of web services time to transition to HTTPS, we will support separate HTTP and HTTPS services until the end of 2017. From January 2018 most HTTP traffic will be automatically redirected to HTTPS. [more...] View this page in https
The basic structure of immunoglobulin (Ig)  molecules is a tetramer of two
light chains and two heavy chains linked by disulfide bonds. There are two
types of light chains: kappa and lambda, each composed of a constant domain
(CL) and a variable domain (VL). There are five types of heavy chains: α,
delta, epsilon, γ and mu, all consisting of a variable domain (VH) and
three (in α, delta and γ) or four (in epsilon and mu) constant
domains (CH1 to CH4).
The major histocompatibility complex (MHC) molecules are made of two chains.
In class I  the α chain is composed of three extracellular domains, a
transmembrane region and a cytoplasmic tail. The β chain (β-2-microglobulin) is composed of a single extracellular domain. In class II ,
both the α and the β chains are composed of two extracellular domains,
a transmembrane region and a cytoplasmic tail.
It is known [4,5] that the Ig constant chain domains and a single
extracellular domain in each type of MHC chains are related. These
homologous domains are approximately one hundred amino acids long and
include a conserved intradomain disulfide bond. We developed a small pattern
around the C-terminal cysteine involved in this disulfide bond which can be
used to detect these category of Ig related proteins.
April 2006 / Pattern revised.
PROSITE method (with tools and information) covered by this documentation:
Trends Biochem. Sci. 6:203-205(1981).
Klein J., Figueroa F.
Immunol. Today 7:41-44(1986).
Figueroa F., Klein J.
Immunol. Today 7:78-81(1986).
Orr H.T., Lancet D., Robb R.J., Lopez de Castro J.A., Strominger J.L.
The heavy chain of human histocompatibility antigen HLA-B7 contains an immunoglobulin-like region.
PROSITE is copyright. It is produced by the SIB Swiss Institute
Bioinformatics. There are no restrictions on its use by non-profit
institutions as long as its content is in no way modified. Usage by and
for commercial entities requires a license agreement. For information
about the licensing scheme send an email to
or see: prosite_license.html.