While proper activity is desired when creating a peptide, there are other considerations that must be accounted for. A specific sequence may be ideal for proper study or function, but if the sequence makes synthesis or purification difficult, it may be necessary to reevaluate the sequence. The peptide? properties will be intrinsically affected by the chemical makeup of its individual amino acids and their interactions with other residues, as well as the length of the amino acid sequence, and the hydrophobicity of the amino acids. We offer wide range of purity selections from crude to >70%, 80%, 90%, 95% and >98% in various quantities (mgs to grams).
Amino Acid Properties (at neutral pH)
Acidic Amino Acids?sp (D) and Glu (E)
Basic AminoAcids?rg (R), His (H), and Lys (K)
Non-polar and Hydrophobic?la (A), Gly (G), Ile (I), Leu (L), Phe (F), Pro (P) and Met (M)
Aromatic Amino Acids?he (F), Tyr(Y) ,Trp (W)
Polar but uncharged?sn (N), Cys (C), Gln(Q), Thr(T), Tyr(Y) and Trp(W)
Form Covalent Bond (disulfide bridge)?ys (C)
Common Phospho-amino acids?er(PO3), Thr(PO3) and Tyr(PO3)
Peptide Stability
Aspartic Acid is susceptible to cyclic imide formation through a dehydration reaction. Sequences containing DG or DS have higher probability dehydration.
Cysteine, Methionine and Tryptophan have a tendency to oxidize.
Secondary structure may promote aggregation, also making peptides more difficult to resuspend. In particular, beta-sheet formation can cause incomplete solvation of the peptide and in turn would inhibit proper synthesis. The result could be deletion products and/or high difficulty in purification. Valine, isoleucine, tyrosine, phenylalanine, tryptophan, leucine, glutamine, and threonine are prone to beta-sheet formation and if possible, long stretches of these residues in combination or individually, should be avoided
Solubility considerations
When designing a peptide, it is extremely important to keep in mind the solubility of the peptide. Long stretches of hydrophobic amino acids often cause difficulty in producing and/or purifying the peptide. Difficulty in resuspension may also make the peptide difficult to handle in experimental application. Please consult with our Amino Acid Properties to find out more about the characteristics of your peptides.
Through our proprietary purification techniques, purifying hydrophobic peptides, such as amyloids fragments, are possible. Please note longer delivery time may occur.
