GPR endopeptidase (EC 3.4.24.78, germination proteinase) is an enzyme. This enzyme catalyses the following chemical reaction: Endopeptidase action with P4 Glu or Asp, P1 preferably Glu > Asp, P1' hydrophobic and P2' Ala This enzyme participates in spore germination in Bacillus megaterium.