Synthesis of immunoglobulin in membrane-bound or secretory form is determined by: AIIMS12
|A||1 turn-2 turn joining rule|
|C||Differential RNA processing|
Mature B cells carry membrane antibody (IgM and IgD) on their surfaces. However, on activation secretory form of antibody is also produced. These 2 types of antibodies differ in their C-terminal domains of H chains. The S antibody has a hydrophilic C domain of about 20 amino acids. This is longer in the mAb containing 40 amino acids which comprises the following 3 parts: an extra cellular hydrophilic domain of variable length, a trans-membrane domain of about 26 amino acids and a cytoplasmic tail of variable length. Differential RNA processing followed by polyadenylation is responsible for this differential expression of antibody.