Peptide Modification
Core Techniques for Peptide Modification:
**Cycling:** Forming cyclic structures (such as disulfide bonds) through side chain or terminal linkages to enhance resistance to enzymatic degradation, as seen in natural cyclic peptide drugs.
**PEG Modification:** Introducing polyethylene glycol chains to improve solubility and half-life; for example, smegglutinin uses PEG to prolong its in vivo circulation time.
**Terminal Modification:** Acetylation, amidation, or other treatments at the N-terminus or C-terminus to reduce immunogenicity and optimize metabolic pathways.
(1) Introduction to Fluorescent Labeling: There are three commonly used and relatively cost-effective fluorescent dyes: FITC, Rhodamine B, and Fam. In addition to being proficient in labeling these three fluorescent dyes, Taopu Biotechnology can also label various other fluorescent dyes.
(2) Introduction to PEG Modification: PEG can be divided into two main categories according to its degree of polymerization: one is a low degree of polymerization with a defined molecular weight, and the other is a high degree of polymerization with only an average molecular weight. For example, in PEG2000, the 2000 does not refer to the degree of polymerization, but rather that the average molecular weight of this polymer is around 2000. In order to facilitate the modification of peptides, the active groups at both ends of PEG are usually modified to give it free carboxyl groups, thiol groups, amino groups, or maleimide, etc.
(3)Cyclic Peptide Synthesis
1. Introduction to Site-Specific Cycling Modification: Cycling is of great significance for linear peptides, as it can change their spatial structure and enhance their stability. Our company, Taopu Biotechnology, possesses highly mature cyclic peptide modification technology. We can meet your needs for different types of cyclic formation. Cycling can be broadly classified into two categories: ① Amide rings ② Disulfide rings
2. Amide Ring Modification: Amide rings can be formed by the amino group at the N-terminus and the carboxyl group at the C-terminus of the polypeptide sequence forming an amide bond, or by the amino group and carboxyl group on the side chain of the sequence forming a ring.
(4) Introduction to protein conjugation: Protein conjugation is often used in antibody preparation. Generally, polypeptides are haptens, which are easily digested by enzymes in the body. After conjugation with large protein molecules, they become complete antigens. The three commonly used carrier proteins are BSA, KLH and OVA.
List of Modification
|
N,C-terminal Modification |
Special Amino acid |
Fluorescence/Dye labeling |
Cyclic Peptide |
Quenched Fluorescent Peptide |
Multiple Antigenic Peptide System |
|
Acetylation (N-Terminal), HYNIC (N-Terminal), DTPA (N-Terminal), Formylation (N-Terminal) Fatty acid (N-Terminal) Myristic acid (N-Terminal) Palmytolyl (N-Terminal) Benzyloxycarbonylation (CBZ) Amidation (C-Terminal) Succinylation (Suc, N-Terminal) |
D-Arg, D-Cys, D-Asp, D-Asn, D-Glu, D-Gln, D-Ser, D-His, D-Thr, D-Trp, D-Leu,D-Ile, D-Met, D-Pro, D-Val ,D-Phe, pGlu, Hyp, D-Lys,D-Tyr, D-Orn, Orn, Abu, Aib, (D)1-Nal, (D)2-Pal, (D)4-Cl-Phe, Nva, Nle, Hse, Hcy, Pen, Mpa,N-Methyl amino acid (Ala, Phe, Leu, Ile, Val, Gly,Met),Other amino acid, Dinitrobenzoylation (Lys), Lys(Me2), Phosphorylation (Tyr, Ser, Thr, single site), Tyr(SO3H2), Ser(octanoic acid) |
Biotin (N-Terminal, Y/N Ahx), Biotin (Lys in sequence) Biotin (without Lys in sequence) FITC/5-FAM (N-Terminal, Y/N Ahx) Dansyl (N-Terminal, Y/N Ahx) MCA (N-Terminal) p-Nitroanilide(pNA, C-Terminal) AMC (C-Terminal) |
Disulfide bridge 1st Disulfide bridge 2nd Disulfide bridge 3rd Amide cyclic (Side chain, end) |
Abz/ Tyr (3-NO2), EDANS/DABCYL |
Asymmetric 4 branches Asymmetric 8 branches |
More peptide modification types please contact us for details and price direclty!
