Editor-in-Chief: Brüne, Bernhard
Editorial Board Member: Buchner, Johannes / Lei, Ming / Ludwig, Stephan / Sies, Helmut / Turk, Boris / Wittinghofer, Alfred
SCImago Journal Rank (SJR) 2015: 1.607
Source Normalized Impact per Paper (SNIP) 2015: 0.751
Impact per Publication (IPP) 2015: 2.609
Kinetic properties of cathepsin D and BACE 1 indicate the need to search for additional β-secretase candidate(s)
1Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
2Department of Immunology, The Weizmann Institute of Science, Rehovot, Israel
Citation Information: Biological Chemistry. Volume 389, Issue 3, Pages 313–320, ISSN (Online) 14374315, ISSN (Print) 14316730, DOI: 10.1515/BC.2008.025, March 2008
- Published Online:
Many studies suggest that BACE 1 is the genuine β-secretase; however, this is not undisputed. The wild-type (WT) β-site of the amyloid precursor protein (APP) present in the worldwide population is cleaved very slowly (k cat/K m: approx. 50 m -1 s-1), while proteases acting on relevant substrates are much more efficient (k cat/K m: 104–106 m -1 s-1). Knock-out of BACE 1 in mouse markedly reduces Aβ formation. Nevertheless, studies in other systems show that knock-out experiments in rodents and corresponding genetic defects in human may reveal different phenotypes. Considering these issues, we searched for other β-secretase candidate(s), identified cathepsin D, and evaluated properties of cathepsin D related to BACE 1 that were not examined previously. The kinetic constants (k cat, K m, k cat/K m) for cleaving peptides with β-sites of the WT or the mutated Swedish families (SW) APP by human BACE 1 and cathepsin D were determined and found to be similar. Western blots reveal that in human brain cathepsin D is approximately 280-fold more abundant than BACE 1. Furthermore, pepstatin A strongly inhibits the cleavage of SW and WT peptides by both brain extracts and cathepsin D, but not by BACE 1. These findings indicate that β-secretase activity observed in brain extracts is mainly due to cathepsin D. Nevertheless, as both BACE 1 and cathepsin D show poor activity towards the WT β-site sequence, it is necessary to continue the search for additional β-secretase candidate(s).
Here you can find all Crossref-listed publications in which this article is cited. If you would like to receive automatic email messages as soon as this article is cited in other publications, simply activate the “Citation Alert” on the top of this page.