/**
* Calculates mass in daltons.
* $protein is a sequence of characters
**/
function proteindb_mass($protein)
{
global $proteindb_proteins;
$mass = 0.0;
for ($i = 0; $i < strlen($protein); $i++) {
$amino = $protein[$i];
if (proteindb_is_amino_acid($amino)) {
$mass += $proteindb_proteins[$amino][2];
}
}
// this is combined mass of these amino acids, but they are linked
// Subtract water molecules from peptide bonds.
$mass -= (proteindb_count_amino($protein) - 1) * 18.02;
return $mass;
}
echo @$_POST['protein'];
?>
</textarea><br>
<input type="submit" value="Analyze">
</form>
<?php
ini_set('error_reporting', E_ALL);
ini_set('display_errors', 1);
include_once 'proteindb.php';
if (@$_POST['protein']) {
$protein = $_POST['protein'];
?>
<hr>
Total amino acids: <?php
echo proteindb_count_amino($protein);
?>
<br>
Mass: <?php
echo proteindb_mass($protein);
?>
Da<br>
Aromatic amino acids: <?php
echo proteindb_count_with_property($protein, 'aromatic');
?>
<br>
Aliphatic amino acids: <?php
echo proteindb_count_with_property($protein, 'aliphatic');
?>
<br>
Positive amino acids: <?php