AMPK, PAN-AMPK, western blot
Adenosine monophosphate activated protein kinase or AMPK is not a single protein, but is a trimeric enzyme composed of $\alpha$, $\beta$, and $\gamma$ subunits. There are 2 alpha genes, 2 beta genes, and 3 gamma genes, each coding for closely-related but not identical isoforms. In addition, like most protein kinases (and many other proteins), it is regulated by the phosphorylation and dephosphorylation of some of its residues, most notably Thr172, but at numerous other locations as well.
A &quot;pan-AMPK&quot; antibody will bind all of the AMPK isoforms independently of phosphorylation or other post-translational modification (PTM) state. There are also isoform-specific total AMPK antibodies that just bind the $\alpha2$ subunit, or all 3 $\gamma$ subunits, for example. Finally, there are phospho-specific antibodies to various residues that only bind when the protein is phosphorylated at that site.
Both the pan and isoform-specific antibodies are known as &quot;total&quot; antibodies, as they bind independently of PTMs and will show the total amounts of their target(s) on a Western blot, for example.

Source:
I used to be a Product Scientist for a company that makes antibodies, PTM-specific and total, to AMPK and many other targets.