MS identification of Hsp83 as a nuclear protein bound to JHRR. Nuclear proteins isolated from methoprene- or DMSO-treated Kc cells were purified through the polymerized JHRR affinity column and subjected to HPLC-MS/MS analysis. The R.EMLQQNKVLK.V peptide fragment of Hsp83 was detected in the purified nuclear proteins isolated from methoprene-treated Kc cells but not from the DMSO-treated control Kc cells. PepCount, 3; UniquePepCount, 1; MW, 81865.49; PI, 4.91; MH+, 1247.4903; Diff(MH+), 0.2713; Charge, 2; Rank, 1.