Custom Peptide Modifications
The peptide modification services at GenScript offer a wide range of modifications to meet any research need. These modifications can improve overall peptide stability, alter structure to better understand biological function, or enhance immunogenicity for antibody development and production. In addition to a variety of terminus and internal modifications, GenScript's services include peptide labeling and conjugations for imaging and detection needs.
For a list of our available modifications, select the modification options below:
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N-terminal modifications
5-FAM BSA (-NH2 of N terminal) Hexanoic acid PEN 5-FAM-Ahx CBZ HYNIC Stearic acid Abz Dansyl KLH (-NH2 of N terminal) Succinylation Acetylation Dansyl-Ahx Lauric acid TMR Acryl Decanoic acid Lipoic acid Alloc DTPA Maleimide Benzoyl Fatty Acid MCA Biotin FITC Myristoyl Biotin-Ahx FITC-Ahx Octanoic acid BOC Fmoc OVA (-NH2 of N terminal) Br-Ac- Formylation Palmitoyl -
C-terminal modifications
AFC MAPS Asymmetric 2 branches AMC MAPS Asymmetric 4 branches Amidation MAPS Asymmetric 8 branches BSA (-COOH of C terminal) Me Bzl NHEt Cysteamide NHisopen Ester (OEt) NHMe Ester (OMe) OSU Ester (OtBu) OVA (-COOH of C terminal) Ester (OTBzl) p-Nitroanilide KLH (-COOH of C terminal) tBu -
Special amino acids
{d-ALA}
Alanine{NVA}
Norvaline{pTYR}
Phosphorylation (TYR){Lys(biotin)}
Biotin Lysine{D-2-Nal} {L-4-Pal} {Mini-PEG1} {PEG2}
NH2-(PEG)2-CH2COOH{d-ARG}
Arginine{d-NVA}
Norvaline{gamma-GLU}
Gamma-GLU{Cys(Acm)}
Cysteine (Acm){D-3-Pal} {Lys(5-FAM)} {Met(O)}
Methionine sulfoxide{PEG6}
NH2-(PEG)6-CH2CH2COOH{d-ASN}
Asparagine{ORN}
Ornithine{d-gamma-GLU}
D-Gamma-GLU{Cys(tBu)}
Cysteine (tBu){D-4-F-Phe} {Lys(Dansyl)} {Met(O)2}
Methionine sulfone{PEG11}
NH2-(PEG)11-CH2COOH{d-ASP}
Aspartic Acid{d-ORN}
Ornithine{CIT}
Citrulline{d-1-NAL}
(D) 1-Nal{D-4-I-Phe} {Lys(FITC)} {Cpg}
Cyclopentylglycine{PEG12}
NH2-(PEG)12-CH2CH2COOH{d-CYS}
Cysteine{PEN}
Penicillamine{nme-ALA}
N-methylated ALA{L-1-NAL}
(L) 1-NAL{D-4-NO2-Phe} {Lys(Me)} {Pra}
PropargylglycineDab(Dnp) {d-GLU}
Glutamic Acid{d-PEN}
Penicillamine{nme-ILE}
N-methylated Isoleucine{d-2-PAL}
(D) 2-PAL{D-4-Pal} {Lys(Me2)} {Tic}
1,2,3,4-Tetrahydroisoquin
oline-3-carboxylic acidDap(Dnp) {d-GLN}
Glutamine{d-PHE}
Phenylalanine{nme-LEU}
N-methylated Leucine{L-2-PAL}
(L) 2-PAL{D-Beta-Asp} {Lys(Me3)} {Sec}
SelenocysteineDpa {HCY}
Homocysteine{d-PRO}
Proline{nme-PHE}
N-methylated Phenylalanine{d-4-CL-PHE}
(D) 4-CL-PHE{D-Cha} {Lys(TMR)} {Se-Met}
SelenomethionineLys(Dde) {d-HIS}
Histidine{d-SER}
Serine{nme-VAL}
N-methylated Valine{L-4-CL-PHE}
(L) 4-CL-PHE{D-Chg} {NMe-Asp} {Lys(N3)}
Azido-LysineLys(ivdde) {HSE}
Homoserine{d-THR}
Threonine{nme-SER}
N-methylated Serine{ABU}
Abu{D-Cit} {NMe-Glu} {Beta-HomoLeu}
Beta-HomoLeucineOic {d-HSE}
Homoserine{d-TRP}
Tryptophan{nme-THR}
N-methylated Threonine{AIB}
Aib{Dab} {NMe-Nle} {Cys(Cam)}
Carboxyamidomethy
lated CysteinePip {d-ILE}
Isoleucine{d-TYR}
Tyrosine{nme-TYR}
N-methylated Tyrosine{MPA}
Mpa{Dap} {NMe-Nva} {Arg(Me)}
Methylation at the side chain of ArginineTle {d-LEU}
Leucine{d-VAL}
Valine{alpha-ABA}
Alpha Amino-Butyric Acid{HYP}
Hydroxy Proline{L-2-Nal} {Phg} {ADMA}
Arg(Me)2 asymmetrical{d-LYS}
Lysine{pGLU}
Pyroglutamate{Beta-Asp}
Beta-ASP{Lys-Ac}
Acetylation at the side chain{L-3-Pal} {Ser(octanoic-acid)} {SDMA}
Arg(Me)2 symmetrical{d-MET}
Methionine{Lys(Dnp)}
Dinitrobenzylation (LYS){Ac-LYS}
Acetylation at alpha amine group{Cha} {L-4-F-Phe} {d-HCY}
Homocysteine{Beta-Ala}
Beta-Alanine{NLE}
Norleucine{pTHR}
Phosphorylation (THR){2-Me-ALA}
2-Methyl Alanine{Chg} {L-4-I-Phe} {d-pGLU}
Pyroglutamate{GABA}
4-Aminobutyric acid{d-NLE}
Norleucine{pSER}
Phosphorylation (SER){nme-GLY}
N-methylated Glycine{D-2-Me-Trp} {L-4-NO2-Phe} {nme-MET}
N-methylated Methionine{Ahx}
6-amino-hexanoic acid -
Stable isotope labeled peptides
Arg(13C6,15N4) Ile(13C6,15N) Leu(13C6,15N) Lys(13C6,15N2) Val(13C5,15N) -
Fluorescent peptide modifications/FRET pairs
1-Pyrenemethylamine HCL FITC (N-Terminal) 5-FAM (N-Terminal) FITC-Ahx (N-Terminal) 5-FAM-Ahx (N-Terminal) Glu(EDANS)-NH2 Abz (N-Terminal) MCA (N-Terminal) Abz/DNP MCA/DNP Abz/Tyr (3-NO2) Quenched fluorescent peptide DABCYL Tyr (3-NO2) DABCYL/Glu(EDANS)-NH2 TMR Dansyl (N-Terminal) AMC Dansyl-Ahx (N-Terminal) EDANS/DABCYL -
Peptide conjugates
BSA (-COOH of C terminal) BSA Conjugation on cysteine KLH (-NH2 of N terminal) KLH Conjugation on cysteine OVA (-COOH of C terminal) OVA (-NH2 of N terminal) OVA Conjugation on cysteine -
Other modifications (MAPS, PEGylation, cyclic modifications)
MAPS PEGylation Cyclic modifications Disulfide Bridges Other MAPS Asymmetric 2 branches (C-Terminal) Mini-PEG1 Head to tail Cyclic Disulfide Bridge BOC MAPS Asymmetric 4 branches (C-Terminal) Mini-PEG2 Double Disulfide bridge tBu MAPS Asymmetric 8 branches (C-Terminal) {PEG2}
NH2-(PEG)2-CH2COOHMono Disulfide bridge Succinylation {PEG6}
NH2-(PEG)6-CH2CH2COOHTriple Disulfide Bridge Me {PEG11}
NH2-(PEG)11-CH2COOHp-Nitroanilide {PEG12}
NH2-(PEG)12-CH2CH2COOHp-Nitroanilide
If the peptide is from an internal sequence of a protein, terminal amidation (C-terminus) or acetylation (N-terminus) will remove its charge and help it imitate its natural structure (amide, CONH2). In addition, this modification makes the resulting peptide more stable towards enzymatic degradation resulting from exopeptidases.
For C-terminal labeling of biotin, a Lys residue is added to the C-terminus of the peptide. Biotin is then attached to the lysine side chain via amide bond. The positive charge of the lysine is then removed.
Fluorescein isothiocyanate (FITC) is an activated precursor used for fluorescein labeling. For efficient N-terminal labeling, a seven-atom aminohexanoyl spacer (NH2-CH2-CH2-CH2-CH2-CH2-COOH) is inserted between the fluorophore (fluoroscein) and the N-terminus of the peptide.
Peptide cyclization can be achieved through creating disulfide bridges between cysteine residues on the peptide. This is a challenging practice for peptide containing multiple cysteine residues due to random formations of disulfide bridges between them. GenScript is able to build disulfide bridges between cysteine at specified positions. We are able to introduce up to three customized disulfide bridges on one peptide.
Phosphopeptides can assist in the investigation of the influences of phosphorylation on peptides and protein structure and in the understanding of regulatory processes mediated by protein kinases. GenScript has successfully synthesized numerous serine-, threonine-, and tyrosine-phosphopeptides. For peptides containing one or more of these hydroxy-amino acids, selective phosphorylation can be achieved by orthogonal protection or by Fmoc-protected phosphorylated amino acids.
Delivery Specifications
All peptide synthesis is subject to GenScript's stringent quality control. The typical delivery consists of lyophilized peptide of the required sequence, purity, and quantity and associated QC reports.
For quotations, please use our Secure Instant Online Quotation/Order system. However, you may also contact us by email, phone (1-732-885-9188), fax (1-732-210-0262), or via our Secure Messaging System.
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