Antibody Structure Problem Set

Problem 6. Antibody specificity

Replacing the antigen's glutamine 121 with histidine greatly decreases the affinity of the antibody for lysozyme. The best explanation for the difference in affinities is that histidine can't fit into the depression occupied by glutamine. An important implication of this observation:

A.	minor changes in antigen structure can dramatically change immune recognition
B.	pathogens that mutate frequently are more difficult for the immune system to eliminate
C.	A and B are true