PLPERL function error - utf-8 to iso8859-1

Trying to create a plperl function to strip non-friendly mainframe
characters from a string. However, when I try to add the Trademark symbol
(™) as a replace criteria, PG spits back an error:
ERROR: Could not convert UTF-8 to ISO8859-1
Any way I get around this?

CREATE OR REPLACE FUNCTION public.mainframe_description(varchar)
RETURNS varchar AS
'
my($desc) = @_;
$desc =~ s/®//g;
$desc =~ s//e/g;
$desc =~ s/ô/o/g;
$desc =~ s/æ/E/g;
$desc =~ s/Ò/ /g;
$desc =~ s/Ó/ /g;
$desc =~ s/è/e/g;
$desc =~ s/Ô//g;
$desc =~ s/É/E/g;
$desc =~ s/°//g;
$desc =~ s/é/e/g;
$desc =~ s/~Y//g;
$desc =~ s/Ö//g;
/*Error happens here */
$desc =~ s/™//g;
return $desc;
'
LANGUAGE 'plperl' VOLATILE;
COMMENT ON FUNCTION public.mainframe_description(varchar) IS 'Return a
clean description for mainframe input';

TIA

Patrick Hatcher