BIOL 2050U Lecture Notes - Tx Network, Immunoglobulin G, Somatic Hypermutation
Document Summary
Constant portion alleles are encoded on a single locus. Antibody sequence variability is clustered variability = # of different observed aa"s/ frequency of most common range = 1(least) 400(most) observe clustering in 3 hypervariable regions interspersed by framework regions true for light and heavy chains. **hypervariable regions involved in antigen binding** also called cdr"s (complementarity determining regions) 3d structure of antibody domains: all domains have immunoglobulin fold all fold ind. into a globular domain and there is interaction between hc and lc (vh interacts w/ vl) Three hypervariable regions brought together as three loops that extend from ends of vh and vl. Epitope = minimal amt of antigen needed to bind antibody. Generation of variable region diversity by v(d)j recombination. Kappa genes are on single genetic locus but associate w/different vregions. V regions are encoded by multiple gene segments (somatic recombination) Hc and lc are coded piecewise- brought together by site specific recomb. during b-cell differ.
