Bodog 100k, folding KA in SB to large unusual raise

[PokerAmateur4]

8 players, 100k guaranteed bodog.

Sorry if I label positions wrong.

30/60 blinds

UTG(t600) fold, UTG+1(t2700) fold, MP1(t6700) call 60, MP2(1580) raise 520, CO(3500) fold, Button(810) fold, Hero(1305).....

MP2 had been playing somewhat tightly but a hand ago made a minimum raise LP which gave me a slight inkling that she was playing more agressivley, stealing where it looks possible.

MP1 has given me every indication that he raises his hands PF which are strong, so he was not an issue.

Thinking quickly I decided to fold. Later I mulled over the decision cursing to myself. Do you think I made the right decision? Why?