Structural and chemical complementarity between antibodies and the crystal surfaces they recognize

Area of Science:

• Immunology
• Structural Biology
• Crystallography

Background:

• Monoclonal antibodies (mAbs) can exhibit high specificity for crystalline structures.
• Understanding the molecular basis of antibody-crystal interactions is crucial for developing diagnostic and therapeutic tools.

Purpose of the Study:

• To determine the variable region sequences of three mAbs with distinct specificities to cholesterol monohydrate and 1,4-dinitrobenzene crystals.
• To model the binding site structures of these mAbs based on homology to known antibody structures.
• To elucidate the structural basis for specific recognition of different crystal faces.

Main Methods:

• Sequencing of monoclonal antibody variable regions.
• Homology modeling of antibody binding sites.
• Analysis of predicted binding site structures and amino acid compositions.

Main Results:

• Sequences of three mAbs with specificities to cholesterol monohydrate and 1,4-dinitrobenzene were determined.
• Binding site models revealed distinct structural features complementary to specific crystal faces.
• One antibody's binding site was predicted to be step-shaped, interacting with a stepped cholesterol crystal face via hydrophobic and hydrophilic interactions.
• Another antibody's binding site was modeled as flat, with aromatic and polar residues complementary to a flat 1,4-dinitrobenzene crystal face.

Conclusions:

• Antibody binding site structure is a key determinant of specific crystal face recognition.
• Complementarity in shape and chemical properties between the antibody binding site and the crystal surface facilitates specific interactions.
• These findings provide insights into antibody-antigen recognition at the crystal-molecule interface.