Frederic Langlois wrote:
> [...]
> 2) Then I searched many databanks and found GFP's amino acid sequence. I
> used this equation to find GFP's mass:
>> mass = [(n1*molecular
> weight1)+(n2*mol.weight2)+...(n20*mol.weight20)]/[(n1+n2+...n20-1)*33g/mol]
>> where 1=glycin; 2 to 20= all the other amino acids
> n=the sum of the amino acids of each kind
> 33g/mol=a water molecule's molecular weight (approximately)
>> I substrated the water molecules that are "lost" when the peptidic bonds are
> made.
>> I converted the molecular weight in Dalton units...
>
I don't understand why do you divide by (n1+n2...+n20-1)*33g/mol
being N the total aa numer: (n1+n2...n20-1) = N-1
and 18 g/mol the water MW,
the correct formula is to SUBTRACT (N-1)*18, not divide by it...
Sergio