#!/usr/bin/perl
use Bio::SeqIO;
use Bio::Seq;
use Bio::Tools::SeqStats;

$in = Bio::SeqIO->new(-file=>'prot.fasta', -format=>'Fasta');
while ( $seqobj = $in->next_seq() ) {
	print "Seq ID: ", $seqobj->display_id(), "\n";
	print "Seq Desc: ", $seqobj->desc(), "\n";
	print "Sequence: ", $seqobj->seq(), "\n";

	$seqstat = Bio::Tools::SeqStats->new($seqobj);
	$mwt_ref = $seqstat->get_mol_wt();
	$mwt = @$mwt_ref[0];
	print "Molecular weight (Dalton): $mwt\n";
}