Title : Complete amino acid
sequence of a mouse immunoglobulin alpha
chain (MOPC 511)
Abstract :
- The complete amino acid sequence of the 432-residue heavy (alpha) chain of mouse myeloma MOPC 511 has been determined
- The variable region of the alpha chain of IgA 511, a phosphocholine-binding protein , is highly homologous to that of the other phosphocholine-binding immunoglobulins
- Comparison of the 511 alpha chain constant region with that of other mouse and human heavy chains shows that sequence divain
- The CH3 domain disulfide bridge of the 511 alpha chain , for example, consists of only 28 amino acid residues compared to 60 residues for other chains and domains
- Sequence divergences are alsos apparent at the CH2/CH3 domain boundary, an area where a number of frameshift mutations have occurred
- One mutant, mouse IgA 47A, lacks the entire CH3 domain
- Comparison of the 511 alppha chain with the 47A alpha chain reveals two noncconservative amino acid changes at the COOH terminus of the 47A chain , Ser-Gln for VAl-Thr in the 511 chain
- These changes and the deletion of the CH3 domain can be explained by a single genetic event--namely, a frameshift mutation followed by premature chain termination
- The remainder of the 47A constant region , including the hinge region , is identical to the 511 alpha chain , except for two conservative changes in the CH1 domain : serine-126 and theonine-197 in the 511 alpha chain are both replaced by alanine in the 47A chain
Output (sent_index, trigger,
protein,
sugar,
site):
Output(Part-Of) (sent_index,
protein,
site):
*Output_Site_Fusion* (sent_index,
protein,
sugar,
site):