Annotations: 9R2E

SAbDab Antibody Annotation SAbDab Database Homepage

Chain	Chain Class	Chain Subclass	Chain Type	Antigen Name(s)	Provenance Source
B [auth L], F [auth B]	Light Chain	IGLV1	Lambda	isoform 1 of immunoglobulin heavy constant alpha 1	SAbDab (2025-12-19)
A [auth H], E [auth A]	Heavy Chain	IGHV3	-	isoform 1 of immunoglobulin heavy constant alpha 1	SAbDab (2025-12-19)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
C [auth P], D [auth Q]	PF07654	Immunoglobulin C1-set domain (C1-set)	Immunoglobulin C1-set domain		Domain
C [auth P], D [auth Q]	PF00047	Immunoglobulin domain (ig)	Immunoglobulin domain	Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-prote ...	Members of the immunoglobulin superfamily are found in hundreds of proteins of different functions. Examples include antibodies, the giant muscle kinase titin and receptor tyrosine kinases. Immunoglobulin-like domains may be involved in protein-protein and protein-ligand interactions.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
C [auth P], D [auth Q]	Isoform 1 of Immunoglobulin heavy constant alpha 1	binding antigen binding	cellular response to stimulus immune response-regulating cell surface receptor signaling pathway regulation of cellular process response to stimulus signaling positive regulation of biological process cell communication positive regulation of response to stimulus immune response-activating signaling pathway immune response-regulating signaling pathway positive regulation of immune response regulation of immune system process signal transduction positive regulation of immune system process cellular response to stimulus immune response-regulating cell surface receptor signaling pathway regulation of cellular process response to stimulus signaling positive regulation of biological process cell communication positive regulation of response to stimulus immune response-activating signaling pathway immune response-regulating signaling pathway positive regulation of immune response regulation of immune system process signal transduction positive regulation of immune system process regulation of biological process cell surface receptor signaling pathway immune response-activating cell surface receptor signaling pathway immune response B cell receptor signaling pathway biological regulation regulation of response to stimulus immune system process regulation of immune response cellular process antigen receptor-mediated signaling pathway activation of immune response adaptive immune response adaptive immune response based on somatic recombination of immune receptors built from immunoglobulin superfamily domains lymphocyte mediated immunity humoral immune response complement activation humoral immune response mediated by circulating immunoglobulin leukocyte mediated immunity complement activation, classical pathway immunoglobulin mediated immune response immune effector process B cell mediated immunity biological process involved in interspecies interaction between organisms response to other organism defense response antibacterial humoral response defense response to symbiont response to external stimulus antimicrobial humoral response response to biotic stimulus defense response to bacterium defense response to other organism response to stress response to bacterium response to external biotic stimulus multicellular organismal process renal system process system process glomerular filtration renal filtration positive regulation of respiratory burst positive regulation of metabolic process respiratory burst metabolic process regulation of respiratory burst regulation of metabolic process positive regulation of cellular process	protein-containing complex IgA immunoglobulin complex immunoglobulin complex IgA immunoglobulin complex, circulating cellular anatomical structure secretory IgA immunoglobulin complex extracellular region extracellular space polymeric IgA immunoglobulin complex immunoglobulin complex, circulating extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle protein-containing complex IgA immunoglobulin complex immunoglobulin complex IgA immunoglobulin complex, circulating cellular anatomical structure secretory IgA immunoglobulin complex extracellular region extracellular space polymeric IgA immunoglobulin complex immunoglobulin complex, circulating extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle vesicle extracellular membrane-bounded organelle cell periphery plasma membrane membrane dimeric IgA immunoglobulin complex secretory dimeric IgA immunoglobulin complex IgG immunoglobulin complex blood microparticle monomeric IgA immunoglobulin complex
B [auth L], F [auth B]	ARGX-121 Fab fragment light chain	-	-	-
A [auth H], E [auth A]	ARGX-121 Fab fragment heavy chain	-	-	-

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
C [auth P], D [auth Q]	IPR036179	Immunoglobulin-like domain superfamily	Homologous Superfamily
C [auth P], D [auth Q]	IPR003597	Immunoglobulin C1-set	Domain
C [auth P], D [auth Q]	IPR003006	Immunoglobulin/major histocompatibility complex, conserved site	Conserved Site
C [auth P], D [auth Q]	IPR013151	Immunoglobulin-like beta-sandwich domain	Domain
C [auth P], D [auth Q]	IPR050380	Immune Recognition and Response Modulators	Family
C [auth P], D [auth Q]	IPR013783	Immunoglobulin-like fold	Homologous Superfamily
C [auth P], D [auth Q]	IPR007110	Immunoglobulin-like domain	Domain

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
C [auth P], D [auth Q]	Pharos: P01876	breast cancer psoriasis

RCSB PDB Core Operations are funded by the U.S. National Science Foundation (DBI-2321666), the US Department of Energy (DE-SC0019749), and the National Cancer Institute, National Institute of Allergy and Infectious Diseases, and National Institute of General Medical Sciences of the National Institutes of Health under grant R01GM157729.