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Custom and Modified Peptides

Synthetic peptides are divided into two major groups: custom peptides that contain natural L-amino acids, and modified peptides with unnatural amino acids residues.

Custom Peptides

We offer the synthesis of 2 and up to 30 amino acid long residue peptides, composed of standard L-amino acids. C-end of the peptide could be free carboxyl or carboxamide, N-end - free amine or acetylated.

Time of delivery is usually 1-4 weeks and depends on the peptide length, complexity, amount ordered and desired peptide purity.

We offer peptides at different degrees of purity: crude, >70%, >80%, >90%, >95%. Trifluoroacetate is a standard salt form of the final peptide product; nevertheless it's conversion into counter ions such as acetate and hydrochloride is available upon request.

Modified peptides

A wide variety of modified peptides can be divided into several groups. We offer custom synthesis of several types of these modified peptides.

Main sequence modifications

Modified peptides

This group of peptides includes products bearing:

Unusual and rare amino acid residues:
D-amino acids, phosphorylated (Ser, Thr, Tyr), glycosylated (Ser, Thr, Asn), β-amino acids, GABA, ω-amino acids, etc

Unnatural amino acid residues:
synthetic amino acid-like constructions, with heavy (not radioactive) isotopes 13C & 15N, derivatives of polyethylene glycols (PEG) serving as spacers within peptide chain, etc.

C-end modifications

Modified peptides

Acylation with carboxylic acids: formic, acetic, propionic, fatty acids (myristic, palmitic, stearic, etc) succinic, benzoic, carbobenzoxy (Cbz), etc. Biotin, long chain biotin.

N-end modifications

  • Acylation with carboxylic acids: formic, acetic, propionic, fatty acids (myristic, palmitic, stearic, etc) succinic, benzoic, carbobenzoxy (Cbz), etc.
  • Biotin, long chain biotin.
  • Derivatives of dyes such as fluorescein (FITC, FAM, etc), 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-acetic acid, 7-metoxycoumarin-3-acetic acid and other coumarins; rhodamines (5-carboxyrhodamine 110 or 6G, 5(6)-TAMRA, ROX, etc); N-[4-(4-dimethylamino)phenylazo]bezoic acid (Dabcyl), 2,4-dinitrobenzene (Dnp), 5 - dimethylaminonaphthalene - 1 — sulfonic acid (Dansyl) and other dyes.
  • PEGs and their derivatives.
Modifications of side functions of amino acids

In addition to the amino and carboxyl groups, some amino acids have other functional groups not included in a peptide's backbone formation, but still capable of reacting with different reagents. We offer synthesis of modified peptides with many possible combinations of amino acid residue(s)/modifying reagent:

Cysteine (Cys) selectively reacts with derivatives of fluorescein (FITC, IAF), rhodamines (5-TMRIA, 5-TRITC G, etc), 5-[(2- aminoethyl)amino]naphthalene-1-sulfonic acid (EDANS) (EDANS C2 maleimide or iodoacetamide); other dyes, PEGs.

Lysine/Ornitine (Lys/Orn) could be selectively modified with:

  • Biotin, long chain Biotin
  • acylated with carboxylic acids: acetic, propionic, fatty acids (myristic, palmitic, stearic, etc) succinic, benzoic, etc;
  • derivatives of dyes such as fluorescein (FITC, FAM, etc), 7-hydroxy-4-methylcoumarin-3-acetic acid, 7-hydroxycoumarin-3-acetic acid, 7-metoxycoumarin-3-acetic acid and other coumarins; rhodamines (5-carboxyrhodamine 110 or 6G, 5(6)-TAMRA, ROX, etc); N-[4-(4-dimethylamino)phenylazo]bezoic acid (Dabcyl), 2,4-dinitrobenzene (Dnp), 5-dimethylaminonaphthalene-1—sulfonic acid (Dansyl) and other dyes.
  • PEGs

Aspartic/Glutamic acids (Asp/Glu) side carboxyl's of these amino acids could be modified with:

  • N-alkyl amides (alkyl = methyl, ethyl, propyl, octyl, benzyl, etc.), polyethylene glycols (PEGs), amides with α,ω-alkyldiamines (ethylenediamine, 1,3-diamino propane, putrescine, cadaverine, diamino PEGs, etc), piperazine, spermine, spermidine, etc;
  • Biotin (connected through a linker)
  • derivatives of dyes such as 5-[(2-aminoethyl)amino]naphthalene-1-sulfonic acid (EDANS), fluorescein (AMF, FITC cadaverine, FAM with linkers, etc), 7-amino-4-trifuoromethyl coumarin (AFC), 7-amino-4-methyl coumarin (AMC), other coumarins; rhodamines (TAMRA, ROX, sulforhodamine 101, etc) and other dyes.
  • Esters: methyl, ethyl, benzyl, etc.

Aurora's services are available as follows: