This volume of Methods in Enzymology, entitled “Arginase: Structure, Function, and Therapeutic Targeting,” provides a comprehensive, methodology-driven perspective on arginase research spanning molecular, biochemical, and translational domains.

The volume is organized into four sections that reflect the breadth of the field, spanning structural and mechanistic enzymology, inhibitor design and therapeutic development, clinical and metabolic aspects of arginine biology, and the evolutionary and functional diversity of arginase and related enzymes. Chapters cover experimental approaches to enzyme expression, purification, and structural characterization; synthetic and computational strategies for inhibitor discovery; and emerging therapeutic modalities, including antibody-based targeting of specific arginase isoforms, advanced delivery systems, and engineered enzyme formulations.

Importantly, the volume extends beyond classical views of arginase as an enzyme of arginine metabolism, highlighting its broader structural and functional context within the ureohydrolase superfamily and related guanidinohydrolase enzymes, including alternative substrates, catalytic diversity, and roles in microorganisms and plants. These perspectives emphasize arginase function in nitrogen metabolism, host–pathogen interactions, and environmental and physiological adaptation.

By integrating contributions from both academia and industry, this volume emphasizes reproducible methodologies and provides a cohesive “from enzyme to organism” framework, connecting fundamental structure–function relationships with applications in metabolism, vascular biology, and therapeutic development.

• Comprehensive coverage of arginase from structure and mechanism to therapeutic targeting
• Methodology-driven chapters emphasizing experimental design, reproducibility, and analytical approaches
• Integration of academic and industry perspectives on inhibitor development, antibody-based and protein-based strategies, and translational applications