Structural differences between the ectodomains of murine and human CD98hc.

Area of Science:

• Structural Biology
• Immunology
• Drug Discovery

Background:

• The CD98 heavy chain (CD98hc) is a cell surface protein with therapeutic potential in cancer treatment and brain drug delivery.
• Cross-species variability in CD98hc hinders the development and safety assessment of therapeutic antibodies in preclinical models.

Purpose of the Study:

• To determine the crystal structure of murine CD98hc extracellular domain.
• To compare the structure with its human ortholog to identify conserved regions for antibody targeting.

Main Methods:

• X-ray crystallography was used to solve the structure of murine CD98hc.
• Comparative structural analysis was performed between murine and human CD98hc.

Main Results:

• The crystal structure of murine CD98hc extracellular domain was determined.
• A single conserved surface patch on CD98hc was identified, accessible for antibody binding and unaffected by glycosylation or membrane shielding.
• This conserved region is a potential epitope for therapeutic antibodies.

Conclusions:

• The identified conserved epitope on CD98hc is essential for developing cross-species reactive antibodies.
• A surrogate approach using this conserved epitope is necessary for preclinical studies of CD98hc-targeting therapeutics.