| TCID | Name | Domain | Kingdom/Phylum | Protein(s) |
|---|---|---|---|---|
|
8.A.32.1.1 | β-amyloid cleaving enzyme I, BACE1, of 501 aas and 2 TMSs, N- and C-terminal, of the pepsin/retropepsin-like aspartyl protease superfamily. BACE1 amplified reconstituted M-currents, altered their voltage dependence, accelerated activation, and slowed deactivation by physical association with channel proteins in a beta-subunit-like fashion (Hessler et al. 2015). BACE1 has a unique sulfur rich motif (M462xxxC466xxxM470xxxC474xxxC478) in its TMS which is characteristic for proteins involved in copper ion storage and transport. This motif promotes BACE1 trimerization and binding of copper ions in vitro. It conducts copper ions through a constricted, partially solvated, axial pore. A central P472 induced kink enables copper ions to alternate between different coordination sites including the prominent C466 and M470 (Bittner et al. 2018). In the plasma membranes of the brain, an age-related increase in ApoE and unesterified cholesterol was observed while BACE-1 and APP gene expression was decreased (Sánchez-Melgar et al. 2022). | Eukaryota |
Metazoa, Chordata | BACE1 of Homo sapiens (P56817) |
|
8.A.32.1.2 | β-secretase 2 of 518 aas and as many as 5 TMSs in a 2 (N-terminal) + 3 (C-terminal) TMS arrangement, BACE2. BACE2 regulates TMEM38B (TRIC-B; TC# 1.A.62.1.3). TMEM38B, whose expression is dependent on BACE2, modulates calcium release from the ER in ocular melanoma, and inhibition of the BACE2/TMEM38B axis may trigger exhaustion of intracellular calcium release while inhibiting tumor progression (He et al. 2021). It is responsible for the proteolytic processing of the amyloid He et al. 2021). It is responsible for the proteolytic processing of the amyloid precursor protein (APP) (Yan et al. 1999). | Eukaryota |
Metazoa, Chordata | beta-Secretase 2 of Homo sapiens |
|
8.A.32.1.4 | Pro-gastricsin, PGC of 388 aas. It shows a more restricted substrate specificity than pepsin A, but shows preferential cleavage at Tyr-|-Xaa bonds (Hassan et al. 2010). It is a member of the aspartic protease family, including pepsin and chymosin (Richter et al. 1998). It is involved in production of pro-antimicrobial substances in seminal plasma. The crystal structure shows that it is quite similar to that of porcine pepsinogen. The tertiary structure of PGC is bilobal with a large active-site cleft between the lobes. Two aspartyl residues in the center of the cleft, namely Asp32 and Asp215, function as catalytic residues (Hassan et al. 2010). | Eukaryota |
Metazoa, Chordata | Pgc of Homo sapiens |
|
8.A.32.1.5 | Protein aspartic protease in guard cells of 653 aas and 2 TMSs, N- and C-terminal. | Eukaryota |
Viridiplantae, Streptophyta | Asp prtease of Brassica rapa (field mustard) |
|
8.A.32.1.6 | Plasmepsin V in the ER, of 590 aas and 2 TMSs, one N-terminal and one C-terminal (Klemba and Goldberg 2005). | Eukaryota |
Apicomplexa | Plasmepsin V of Plasmodium falciparum |