Germline-Dependent Antibody Paratope States and Pairing Specific V_H-V_L Interface Dynamics

Area of Science:

• Biochemistry
• Structural Biology
• Immunology

Background:

• Antibodies are a rapidly expanding class of biotherapeutics.
• Rational antibody design requires a deep understanding of their structural dynamics.
• Germline antibody gene combinations form the basis of antibody diversity.

Purpose of the Study:

• To investigate the conformational diversity of antibody germline combinations.
• To determine how heavy and light chain pairings influence antibody structure and dynamics.
• To identify key factors for rational antibody engineering.

Main Methods:

• Systematic investigation of 16 germline antibody combinations (4 kappa light chains x 4 heavy chains).
• Analysis of paratope, interdomain interactions, and V_H-V_L interface orientations.
• Comparison of CDR loop conformational diversity, population shifts, and sidechain rearrangement timescales.

Main Results:

• Heavy and light chain pairings strongly influence paratope states and V_H-V_L interface orientations.
• Distinct pairings cause shifts in CDR loop conformations, favoring specific canonical structures.
• Sidechain flexibilities and germline-specific features co-determine antibody stability.

Conclusions:

• Antibody CDR loops are correlated, and their conformations are influenced by heavy/light chain pairing.
• Paired chain interactions define distinct paratope states in solution.
• Considering paired chains is essential for understanding antibody binding sites and therapeutic design.