The Immunogen: GAP43 is very abundant protein which is found concentrated in neurons. One group discovered it as one of three proteins which becomes unregulated during the regeneration of the toad optic nerve (1). Three GAPs (Growth associated proteins) were discovered, and the number 43 comes from the apparent SDS-PAGE molecular weight of the one named GAP43. The HGNC name for this protein is, not surprisingly, GAP43. Later work showed that GAP43 does not run on SDS-PAGE in a fashion which accurately reflects its molecular weight, and that GAP43 proteins from different species may run at different apparent molecular weights. Partly due to these features GAP43 were independently discovered by several different groups and therefore has several alternate names, such as protein F1, pp46, neuromodulin, neural phosphoprotein B-50 and calmodulin-binding protein P-57. In each case the number reflects the apparent SDS-PAGE molecular weight, and underlines the unusual properties of this molecule. Mammalian GAP43 proteins contains only 226-243 amino acids, and so the real molecular weight is 23.61-25.14KDa (to perform such calculations yourself see this link). GAP43 is one of many highly negatively charged extended molecules which lack well defined tertiary structure and which run anomolously on SDS-PAGE. Other examples are microtubule associated proteins MAP2 and tau and the various neurofilament subunits. GAP43 has been extensively studied and is known to be a major protein kinase C substrate and to bind calmodulin avidly. GAP43 is anchored to the plasma membrane by palmitoylation modifications.

Left: Western blots of homogenate of cow cerebellum stained with RPCA-GAP43 . A prominent band running at ~43kDa represents the full length GAP43. Right: Mixed neuron-glial cultures stained with RPCA-GAP43 (red), blue is DNA staining.

Antibody Characteristics: The antibody was raised against the C-terminal peptide of rat and mouse GAP43, which is KEDPEADQEHA, to which an N terminal Cysteine residue was added to allow chemical coupling to Keyhole Limpet Hemocyanin carrier protein. The corresponding C terminal peptide in the human GAP43 sequence is KGEEREADQEHA, which is similar enough that our antibody binds to this also. The antibody is provided in the form of affinity purified solution. Store at 4°C or -20°C. Avoid repeat freezing and thawing.

Suggestions for use: The affinity purified antibody can be diluted to 1:1,000-5,000 for immunofluorescence staining and 1:10,000-50,000 for western blotting. On western blots look for a single major clean band in the range of 43kDa to 57kDa, with some variability depending on the species and the percentage acrylamide used in the SDS-PAGE gel (see above for details).

Omim link: press here.

References:

1. Skene JH, Willard M. Changes in axonally transported proteins during axon regeneration in toad retinal ganglion cells. J. Cell Biol. 89:86-95 (1981).

Price and Availability: - We currently supply 100 microliter aliquots of rabbit serum for $200. Material is in stock and ready for immediate shipping.

Limitations: This product is for research use only and is not approved for use in humans or in clinical diagnosis.

Use of Images or Text: The contents of this page are available for modification and reuse under the terms of the Creative Commons Attribution/Share-Alike License 3.0 and the GNU Free Documentation License, unversioned with no invariant sections, front-cover texts, or back-cover texts. These licences permit modification and reuse, even commercially, as long as authorship credit and a link to this page is given.

©EnCor Biotechnology Inc..