Biochemical and kinetic characterization of BACE1: investigation into the putative species-specificity forβ- andβ′-cleavage sites by human and murine BACE1.

Autor:	Hsiu-Chiung Yang, Xiyun Chai, Mosior, Marian, Kohn, Wayne, Boggs, Leonard N., Erickson, Jon A., McClure, Don B., Wu-Kuang Yeh, Lianshen Zhang, Gonzalez-DeWhitt, Patricia, Mayer, John P., Martin, Jose Alfredo, Hu, Jingdan, Chen, Shu-hui, Bueno, Ana Belen, Little, Sheila P., McCarthy, James R., May, Patrick C.
Předmět:	AMYLOID beta-protein precursor PROTEIN precursors AMYLOID beta-protein AMYLOID GLYCOPROTEINS NEUROCHEMISTRY NEUROSCIENCES BIOCHEMISTRY
Zdroj:	Journal of Neurochemistry; Dec2004, Vol. 91 Issue 6, p1249-1259, 11p
Abstrakt:	β-amyloid peptides (Aβ) are produced by a sequential cleavage of amyloid precursor protein (APP) byβ- andγ-secretases. The lack of Aβ production in beta-APP cleaving enzyme (BACE1)–/– mice suggests that BACE1 is the principalβ-secretase in mammalian neurons. Transfection of human APP and BACE1 into neurons derived from wild-type and BACE1–/– mice supports cleavage of APP at the canonicalβ-secretase site. However, these studies also revealed an alternative BACE1 cleavage site in APP, designated asβ′, resulting in Aβ peptides starting at Glu11. The apparent inability of human BACE1 to make thisβ′-cleavage in murine APP, and vice versa, led to the hypothesis that this alternative cleavage was species-specific. In contrast, the results from human BACE1 transgenic mice demonstrated that the human BACE1 is able to cleave the endogenous murine APP at theβ′-cleavage site. To address this discrepancy, we designed fluorescent resonance energy transfer peptide substrates containing theβ- andβ′-cleavage sites within human and murine APP to compare: (i) the enzymatic efficiency; (ii) binding kinetics of a BACE1 active site inhibitor LY2039911; and (iii) the pharmacological profiles for human and murine recombinant BACE1. Both BACE1 orthologs were able to cleave APP at theβ- andβ′-sites, although with different efficiencies. Moreover, the inhibitory potency of LY2039911 toward recombinant human and native BACE1 from mouse or guinea pig was indistinguishable. In summary, we have demonstrated, for the first time, that recombinant BACE1 can recognize and cleave APP peptide substrates at the postulatedβ′-cleavage site. It does not appear to be a significant species specificity to this cleavage. [ABSTRACT FROM AUTHOR]
Databáze:	Complementary Index
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