Cloning and functional expression of a metalloendopeptidase from human brain with the ability to cleave a beta-APP substrate peptide.
Using a combination of PCR and hybridization screening, we have isolated a cDNA clone for a metalloendopeptidase (h-MP78) from a human temporal cortex library. This 2.5-kb cDNA encodes a 689-amino acid protein with a predicted molecular mass of approximately 78.5 kDa. The primary structure of h-MP78 exhibits high similarity to those of porcine (94%) and rat (92%) thimet oligopeptidase. Expression of the cDNA in HEK-293 resulted in the production of an active enzyme able to cleave a chromogenic beta-APP derived substrate peptide KTEEISEVKM-P-nitro-anilide. RNA blot analysis of various human tissues revealed one major species of h-MP78 mRNA of approximately 2.55 kb. The highest level of mRNA was found in the brain.
Thompson
A
A
Pharma Division, F. Hoffmann-La Roche Ltd, Basel, Switzerland.
Huber
G
G
Malherbe
P
P
D000595:Amino Acid Sequence; D016564:Amyloid beta-Protein Precursor / Q000378:metabolism*; D001483:Base Sequence; D015152:Blotting, Northern; D001921:Brain / Q000378:metabolism*; D002460:Cell Line; D003001:Cloning, Molecular; D017931:DNA Primers; D015870:Gene Expression; D015723:Gene Library; D006801:Humans; D008666:Metalloendopeptidases / Q000096:biosynthesis* / Q000737:chemistry / Q000378:metabolism; D008969:Molecular Sequence Data; D008970:Molecular Weight; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000378:metabolism; D013379:Substrate Specificity; D013702:Temporal Lobe / Q000201:enzymology*; D014162:Transfection
D016564:Amyloid beta-Protein Precursor; D017931:DNA Primers; D012333:RNA, Messenger; D011994:Recombinant Proteins; D008666:Metalloendopeptidases