[Cool Doll]

I need to know if peptide bonds can occur if you mix amino acids in water (for example phosphoserine). Or do you need enzymes for it to happen?

[Yggdrasil]

Peptide bonds between amino acids will not form spontaneously in water.  In the lab, synthetic peptides are made by solid phase synthesis using activated forms of the amino acids (amino acids modified to be more reactive than normal).  In cells, peptides are formed on the ribosome in a reaction that is powered by the hydrolysis of ATP and GTP.

[Cool Doll]

Thanks for the answer. Can they bind in other ways with each other or with other molecules?

[Babcock_Hall]

Do you have a specific amino acid in mind?  The chemistry of cysteine is a special case.

[Cool Doll]

Phosphoserine.

[Babcock_Hall]

Would you like to propose a particular reaction in which phosphoserine might be a reactant?  Then we can discuss its liklyhood.

[Cool Doll]

Tetra Calcium Phosphate + Phosphoserine
Is it possible for phosphoserine to bind to TCP with the carboxyl group in one end and to another TCP crystal with the phosphate end?

[Babcock_Hall]

Offhand I would say that this is plausible.  One thing you could do is to check the Cambridge Structural Database to see what they have on phosphoserine.