Annotations: 3CAA

Domain Annotation: SCOP/SCOPe Classification SCOP-e Database Homepage

Chains	Domain Info	Class	Fold	Superfamily	Family	Domain	Species	Provenance Source (Version)
A	d3caa.1	Multi-domain proteins (alpha and beta)	Serpins	Serpins	Serpins	Antichymotrypsin, alpha-1	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)
B	d3caa.1	Multi-domain proteins (alpha and beta)	Serpins	Serpins	Serpins	Antichymotrypsin, alpha-1	human (Homo sapiens ) [TaxId: 9606 ],	SCOPe (2.08)

Domain Annotation: SCOP2 Classification SCOP2 Database Homepage

Chains	Type	Family Name	Domain Identifier	Family Identifier	Provenance Source (Version)
A	SCOP2B Superfamily	Serpins	8037303	3001563	SCOP2B (2022-06-29)

Domain Annotation: CATH CATH Database Homepage

Chain	Domain	Class	Architecture	Topology	Homology	Provenance Source (Version)
A	2.30.39.10	Mainly Beta	Roll	Alpha-1-antitrypsin	domain 1	CATH (4.3.0)
A	3.30.497.10	Alpha Beta	2-Layer Sandwich	Antithrombin	Chain I, domain 2	CATH (4.3.0)

Protein Family Annotation Pfam Database Homepage

Chains	Accession	Name	Description	Comments	Source
A	PF00079	Serpin (serine protease inhibitor) (Serpin)	Serpin (serine protease inhibitor)	Structure is a multi-domain fold containing a bundle of helices and a beta sandwich.	Domain

Gene Ontology: Gene Product Annotation Gene Ontology Database Homepage

Chains	Polymer	Molecular Function	Biological Process	Cellular Component
A	ANTICHYMOTRYPSIN	DNA binding binding organic cyclic compound binding nucleic acid binding enzyme regulator activity molecular function inhibitor activity peptidase regulator activity serine-type endopeptidase inhibitor activity molecular function regulator activity enzyme inhibitor activity peptidase inhibitor activity endopeptidase regulator activity endopeptidase inhibitor activity	multicellular organismal process maintenance of gastrointestinal epithelium system process digestion multicellular organismal-level homeostasis epithelial structure maintenance homeostatic process digestive system process anatomical structure homeostasis tissue homeostasis regulation of biological process regulation of lipid metabolic process biological regulation primary metabolic process multicellular organismal process maintenance of gastrointestinal epithelium system process digestion multicellular organismal-level homeostasis epithelial structure maintenance homeostatic process digestive system process anatomical structure homeostasis tissue homeostasis regulation of biological process regulation of lipid metabolic process biological regulation primary metabolic process metabolic process regulation of metabolic process lipid metabolic process regulation of primary metabolic process acute-phase response response to stimulus defense response response to stress inflammatory response acute inflammatory response	extracellular region extracellular space cellular anatomical entity blood microparticle extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle vesicle extracellular membrane-bounded organelle vesicle lumen intracellular anatomical structure intracellular vesicle extracellular region extracellular space cellular anatomical entity blood microparticle extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle vesicle extracellular membrane-bounded organelle vesicle lumen intracellular anatomical structure intracellular vesicle membrane-enclosed lumen cytoplasmic vesicle lumen secretory granule lumen intracellular membrane-bounded organelle endomembrane system intracellular organelle lumen intracellular organelle cytoplasmic vesicle organelle lumen secretory granule secretory vesicle cytoplasm cell periphery extracellular matrix external encapsulating structure collagen-containing extracellular matrix platelet alpha granule platelet alpha granule lumen lytic vacuole vacuolar lumen lysosome azurophil granule vacuole azurophil granule lumen primary lysosome nucleus
B	ANTICHYMOTRYPSIN	DNA binding binding organic cyclic compound binding nucleic acid binding enzyme regulator activity molecular function inhibitor activity peptidase regulator activity serine-type endopeptidase inhibitor activity molecular function regulator activity enzyme inhibitor activity peptidase inhibitor activity endopeptidase regulator activity endopeptidase inhibitor activity	multicellular organismal process maintenance of gastrointestinal epithelium system process digestion multicellular organismal-level homeostasis epithelial structure maintenance homeostatic process digestive system process anatomical structure homeostasis tissue homeostasis regulation of biological process regulation of lipid metabolic process biological regulation primary metabolic process multicellular organismal process maintenance of gastrointestinal epithelium system process digestion multicellular organismal-level homeostasis epithelial structure maintenance homeostatic process digestive system process anatomical structure homeostasis tissue homeostasis regulation of biological process regulation of lipid metabolic process biological regulation primary metabolic process metabolic process regulation of metabolic process lipid metabolic process regulation of primary metabolic process acute-phase response response to stimulus defense response response to stress inflammatory response acute inflammatory response	extracellular region extracellular space cellular anatomical entity blood microparticle extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle vesicle extracellular membrane-bounded organelle vesicle lumen intracellular anatomical structure intracellular vesicle extracellular region extracellular space cellular anatomical entity blood microparticle extracellular exosome membrane-bounded organelle extracellular vesicle extracellular organelle organelle vesicle extracellular membrane-bounded organelle vesicle lumen intracellular anatomical structure intracellular vesicle membrane-enclosed lumen cytoplasmic vesicle lumen secretory granule lumen intracellular membrane-bounded organelle endomembrane system intracellular organelle lumen intracellular organelle cytoplasmic vesicle organelle lumen secretory granule secretory vesicle cytoplasm cell periphery extracellular matrix external encapsulating structure collagen-containing extracellular matrix platelet alpha granule platelet alpha granule lumen lytic vacuole vacuolar lumen lysosome azurophil granule vacuole azurophil granule lumen primary lysosome nucleus

InterPro: Protein Family Classification InterPro Database Homepage

Chains	Accession	Name	Type
A	IPR023795	Serpin, conserved site	Conserved Site
A	IPR000215	Serpin family	Family
A	IPR023796	Serpin domain	Domain
A	IPR042178	Serpin superfamily, domain 1	Homologous Superfamily
A	IPR042185	Serpin superfamily, domain 2	Homologous Superfamily
A	IPR036186	Serpin superfamily	Homologous Superfamily
B	IPR023795	Serpin, conserved site	Conserved Site
B	IPR000215	Serpin family	Family
B	IPR023796	Serpin domain	Domain
B	IPR042178	Serpin superfamily, domain 1	Homologous Superfamily
B	IPR042185	Serpin superfamily, domain 2	Homologous Superfamily
B	IPR036186	Serpin superfamily	Homologous Superfamily

Pharos: Disease Associations Pharos Homepage Annotation

Chains	Drug Target	Associated Disease
A	Pharos: P01011	prostate cancer Lipoidosis lysosomal lipid storage disorder psoriasis
B	Pharos: P01011	prostate cancer Lipoidosis lysosomal lipid storage disorder 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.