Limulus clotting factor B

Limulus clotting factor B (EC 3.4.21.85) is an enzyme.^[1] This enzyme catalyses the following chemical reaction:

Selective cleavage of -Arg⁹⁸-Ile⁹⁹- bond in limulus proclotting enzyme to form active clotting enzyme

Limulus clotting factor B
Identifiers
EC no.	3.4.21.85
CAS no.	848851-53-6
Databases
IntEnz	IntEnz view
BRENDA	BRENDA entry
ExPASy	NiceZyme view
KEGG	KEGG entry
MetaCyc	metabolic pathway
PRIAM	profile
PDB structures	RCSB PDB PDBe PDBsum
Search PMC articles PubMed articles NCBI proteins

This enzyme is present in the hemocyte granules of the horseshoe crabs Limulus and Tachypleus. In the immunity-related clotting pathways of these organisms, factor B is downstream of Limulus clotting factor C, but upstream of Limulus clotting enzyme.^[2]