c:\@Work\Perl>perl -wMstrict -le
"my $id  =    '1QJ8:A|PDBID|CHAIN';
 my $str = 'xxx1QJ8:A|PDBID|CHAINxxx';
 ;;
 print qq{matched '$&'} if $str =~ /$id/;
"
matched '1QJ8:A'