const key = `{"address":"6ed233df185d0ee56c3492918469b635faea81ab","crypto":{"cipher":"aes-128-ctr","ciphertext":"9cd4735969a0c892e16fc20f56531cab186bb486269b7811cd2796de56a4e64f","cipherparams":{"iv":"eafc14ea8f7ba581db92dc93b6413cc3"},"kdf":"scrypt","kdfparams":{"dklen":32,"n":262144,"p":1,"r":8,"salt":"66fbaf8592f5bfce507599e766f4f73fb56c567bfd4abd5d340a541235797368"},"mac":"b7227063d3f65e00c50459c430a299fdf9372369acd8f23dbc3eab514b3a0486"},"id":"86d17a64-e9c4-4c6c-ad79-014ea7969c2e","version":3}`

auth, err := bind.NewTransactor(strings.NewReader(key), "")
if err != nil {
    log.Fatalf("error while get NewTransactor: %v", err)
}

transactOpts := bind.TransactOpts{
    From: auth.From,
    Nonce: 0,
    Signer: auth.Signer,
    GasLimit: 200000,
    Context: context.Background(),
}