The
amyloid precursor protein (APP) is a large membrane protein whose N-terminus
projects into the extracellular space. In Alzheimer's disease (AD), the
APP is proteolytically cleaved at the N-terminal of Ab
by b-secretase
(BACE) to release a ~100 kD APPsb protein into the extracellular space.
The remaining 12 kD fragment remains membrane bound where it can be
cleaved at its C-terminus by g-secretase
(presenilins) to release the insoluble Ab
peptide into the extracellular space with the ~8 kD APP C-terminal
fragment (CTFb)
remaining membrane bound. The
APP is the subject of intensive investigations to determine how this
protein is broken down abnormally in AD brain to give rise to Ab,
which is present in senile plaques and vessels.
A goat antiserum to a synthetic peptide that corresponds to
amino acids 44-63 of the N-terminus of human APP is currently available.
This antiserum has been shown to be immunoreactive with the
unconjugated immunizing peptide by ELISA.
The antiserum will immunolabel dystrophic neurites in senile
plaques in both formalin-fixed, paraffin-embedded sections and
paraformaldehyde fixed frozen sections from Alzheimer brain.
It also shows immunoreactivity with APP containing neurons.
In Western blot analysis it immunolabels the intact APP protein in
cell lysates and the cleaved N-terminal APPsb
fragment that is secreted into the medium. This antibody should be a
valuable tool for scientists working to understand the role of APP in
Alzheimer’s disease.
This
antiserum was produced using proprietary methodology whereby the peptide
is attached to a carrier that elicits minimal immunoreactivity so that the
antiserum has a higher degree of specificity for the peptide.
Since there is no overwhelming production of interfering antibodies
to the carrier, this antiserum can routinely be used without further
purification. Pseud-Immune™ control
immune serum (Cat no. GPA018E ) from a mock immunized animal is available
to be used in conjunction with this antibody as well as the immunizing
peptide (Cat no. HSP005N), which can be used to neutralize
immunoreactivity.
Manufacturing
Reference:
Palmer, MR, et al.
Biochem. Biophys. Res. Comm. 156:432-437, 1988.