D. hypervariable region iv. An epitope composed of amino acids from different parts of a polypeptide chain brought together by protein folding 4.5 Fill-in-the-Blanks: Most vertebrates, including humans and mice, produce antibodies composed of ________ and ________ chains. These bear ____ regions that recognize the antigen and ____ regions that dictate the antibody class and isotype. camelids and cartilaginous fish, however, produce ________________ and _______________, respectively, which are forming the basis for single-chain antibody production for clinical applications.
4.6 Multiple Choice: Which of the following statements is not true?
A. T-cell receptor α and β chains pair together, but the α chain can be switched out for a γ or a δ chain.
B. electrostatic interactions (for example, a salt bridge) occur between charged amino acids.
C. hydrophobic interactions occur between two hydrophobic surfaces and exclude water.
D. Antibodies often have many aromatic amino acids such as tyrosine in their antigen-binding sites.
E. Mhc restriction is the phenomenon where T cells will recognize a unique set of peptides bound to a particular Mhc molecule.
4.7 Multiple Choice: Which of the following is the most abundant immunoglobulin class in healthy adult humans and mice?
A. igA
B. igD
C. ige
D. igg
E. igM 4.8 Multiple Choice: Which of the following describes the structure of an immunoglobulin fold?
A. Two antiparallel β sheets with an α-helical linker and a disulfide bond link
B. Two β strands linked by a disulfide bond
C. four α helices linked by two disulfide bonds
D. Seven antiparallel α helices in series
E. one β sandwich of two β sheets folded together and linked by a disulfide bond 4.9 Multiple Choice: Antibodies have flexibility at various points in the molecule, particularly the hinge region between the fc and fab portion and, to some extent, the junction between the V and c regions. Which of the following properties of an antibody are not affected by its flexibility?
A. Binding to small antigens (haptens)
B. Avidity to antigen
C. Affinity to antigen
D. interaction with antibody-binding proteins
E. Binding to distantly spaced antigens 4.10 Multiple Choice: Which region of the antigen receptor of B cells and T cells is most critical in antigen recognition and specificity?
A. fR1 B. cDR1 C. fR2 D. cDR2 E. fR3 F. cDR3 G. fR4
General references.
Garcia, K.C., Degano, M., Speir, J.A., and Wilson, I.A.: Emerging principles for T cell receptor recognition of antigen in cellular immunity. Rev. Immunogenet. 1999, 1:75–90.
Garcia, K.C., Teyton, L., and Wilson, I.A.: Structural basis of T cell recognition. Annu. Rev. Immunol. 1999, 17:369–397.
Moller, G. (ed): Origin of major histocompatibility complex diversity. Immunol. Rev. 1995, 143:5–292.
Poljak, R.J.: Structure of antibodies and their complexes with antigens. Mol. Immunol. 1991, 28:1341–1345.
Rudolph, M.G., Stanfield, R.L., and Wilson, I.A: How TCRs bind MHCs, peptides, and coreceptors. Annu. Rev. Immunol. 2006, 24:419–466.