In the absence of the protein translating catalysts of the cell, what would be required to form a peptide bond between two adjacent amino acids such as that found in a proteins primary structure?

If for example that catalyst was available for the formation of life from non-living tissue, how could amino acids be joined without forming peptide bonds with the side chain functional groups of Lysine, Aspartic acid and glutamic acid? How could pH play a role? Is the ionized state of the functional groups important?