Antibodies that bind with high affinity to some viral surface proteins require heavy chain CDR3 loops of unusual length. Whereas the average human heavy chain CDR3 length is ~15 amino acids, antibodies with V_HCDR3 loops of 30 amino acids are readily detected in the repertoire. These antibody heavy chains with CDR3 lengths of 30 amino acids would likely be missing in individuals lacking:

Question

Antibodies that bind with high affinity to some viral surface proteins require heavy chain CDR3 loops of unusual length. Whereas the average human heavy chain CDR3 length is ~15 amino acids, antibodies with V_HCDR3 loops of >30 amino acids are readily detected in the repertoire. These antibody heavy chains with CDR3 lengths of >30 amino acids would likely be missing in individuals lacking:

Quizplus · Accepted Answer

Terminal deoxy nucleotidyl transferase (TdT) is responsible for adding non-templated nucleotides (N-regions) to the heavy chain gene segments during V(D)J recombination. This process contributes to the diversity of the antibody repertoire and allows for the generation of antibody heavy chains with CDR3 loops of unusual length, such as those observed in antibodies that bind with high affinity to some viral surface proteins. Therefore, individuals lacking TdT would likely be missing these antibody heavy chains with CDR3 lengths of >30 amino acids.

Antibodies That Bind with High Affinity to Some Viral Surface