The presenilin-1 (PS-1) gene was found on chromosome 14 and is responsible for an early onset form of Alzheimer's disease (AD) that accounts for 70-80% of the inherited forms of Alzheimer's. It is a membrane protein that has a region where at least seven mutations have been identified in family members with AD.  The gene sequence of PS-1 does not match any known human gene sequences with the exception of PS-2; but has been found to be a new class of aspartic–proteases.  It has now been identified as one of the g-secretase proteases.

Alzheimer’s disease (AD) is characterized by the progressive formation in the brain of insoluble amyloid plaques and vascular deposits consisting of the 4-kD amyloid b-peptide (Ab).  Ab generation is initiated by proteolytic cleavage of the amyloid precursor protein (APP) at the N-terminal of A$ by $-secretase (BACE).  The A$ peptide is then released by proteolytic cleavage at its C-terminus by g-secretase (presenilins).  Because both these proteases are prime candidates for therapeutic intervention, an intense search has been underway to identify these two enzymes.

A goat antiserum to a synthetic peptide that corresponds to amino acids 14-33 of the N-terminus of the human PS-1 protein is currently available. This antiserum has been shown to be immunoreactive with the unconjugated immunizing peptide by ELISA, but does not show immunoreactivity with the peptide used for the PS-2 antibody. This antiserum immunolabels neurons using formalin-fixed, paraffin-embedded tissue sections. Western blot analysis shows that the antibody immunolabels the intact 48 kD PS-1 protein, as well as the N-terminal fragment of the cleaved from of PS-1 that occurs in brain. This antibody should be a valuable tool for scientists working to understand the role of PS-1 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. HSP006N), which can be used to neutralize immunoreactivity

Manufacturing Reference:

Southwest Immunology, Inc., unpublished results.