• Peptide Calculator:
  • Sequences can be entered in upper case, lower case or mixed case.
  • Select an N-terminal for your peptide.  If you select nothing the default is a free amine.
  • Select a linker.  This is optional.  If you select nothing the default is no linker.
  • Enter your peptide sequence in the text area by using the keyboard or pasting your sequence.
  • Enter 'J' for phoshhoSerine, 'U' for phosphoThreonine and 'O' for phosphoTyrosine and 'Z 'for Norleucine.
  • Enter 'X' for (S)-2(4'-pentenyl)Alanine.  Your sequence must contain two X's.
  • Select a C-terminal for your peptide.  If you select nothing the default is carboxylic acid.
  • The default molecular weight is average.  Use the option button for monoisotopic weights.
  • The default molecular weight is for linear peptides. 
  • Use the 'lactam' option buttons for lactam bridged peptides.  Lactam bridged peptides must contain at least one 'D' (or 'E') and one 'K' in the sequence.
  • Use the 'cyclic' option button for head to tail cyclic peptides.  Cyclic peptides must have 'acid' as the C-terminus and 'amine' as the N-terminus.
  • Use the 'stapled' option button for hydrocarbon stapled peptides.  Your sequence should contain only two X's [(S)-2(4-pentenyl)Alanine] for hydrocarbon stapled peptides.

  • Analog Calculator:
  • The analog calculator can be used to calculate the molecular weights of standard peptides, disulfide-bridged peptides, lactam-bridged peptides, cyclic peptides, hydrocarbon stapled peptides, peptides containing analogs and peptide-pna conjugates.
  • Amino acids or analogs have to selected from the dropdown buttons. Click "add amino acid" button after each amino acid is selected. Click "calculate" to calculate the molecular weight of the peptide. Molecular weigts are monoisotopic in the analog calculator.
  • Click the disulfide bridge option buttons for disulfide bridges. Peptides must contain at least two cysteines to have a disulfide bridge.
  • For the analog calculator, alkeneyl residues are listed as modfications of Alanine under the 'A' dropdown button. Use these for hydrocarbon stapled peptides. Peptides must have two alkenyl groups to be hydrocarbon stapled.
  • For the analog calculator, C-terminal linkers like C-terminal DimainePEG and C-terminal EtyhlDiamine are listed as analogs of 'X'.
  • For the analog calculator, PNA bases and the PNA AEEA spacer are listed as analogs of 'X'.

  • PNA Calculator:
  • The stand alone PNA calculator can be used to calculate the molecular weights of peptide nucleic acids (PNA).
  • PNA sequences can be entered in upper case, lower case or a mixture of cases.  Sequences can also be pasted.  The PNA calculator will convert all characters to lower case.
  • Valid PNA characters are 'a', 't', 'g' and 'c'.  Any other character will give an error.
  • The default N-terminus for PNA is free amine.  Select the 'O' linker for the commonly used PNA AEEA spacer.
  • The default C-terminus for PNA is amide.  Select 'Lysine' or 'Lysine-Amide' if you need these instead.