my $fasta = ">sp|P01815|HV2B_HUMAN Ig heavy chain V-II region COR - Homo sapiens (Human). QVTLRESGPALVKPTQTLTLTCTFSGFSLSSTGMCVGWIRQPPGKGLEWLARIDWDDDKY YNTSLETRLTISKDTSRNQVVLTMDPVDTATYYCARITVIPAPAGYMDVWGRGTPVTVSS "; my @parts = split /\n/, $fasta; my $sequence = join '', @parts[ 1 .. $#parts ];