KLH, BSA, OVA carrier protein coupling service

Peptide carrier protein coupling modification is used to prepare anti peptide antibodies. Individual peptides are usually too small to trigger sufficient immune responses, while carrier proteins with many antigenic epitopes are beneficial for stimulating helper T cells and further inducing B cell immune responses. After modifying the polypeptide with a carrier protein, it triggers an immune response as a whole, producing antibodies that target the polypeptide, linker, and carrier protein.

There are three most common carrier proteins:

KLH (Keyhole Limpet Hemocyanin) is a free blue respiratory pigment found in the hemolymph of certain mollusks, arthropods (spiders and beetles).

Hemocyanin contains two copper ions directly connected to a polypeptide chain, similar to iron containing hemoglobin. It is easily bound to oxygen and dissociates from oxygen, making it the only known copper protein that can reversibly bind to oxygen. When oxidized, it appears blue-green, and when reduced, it appears white. Due to its higher immunogenicity than BSA, KLH is the most commonly selected carrier protein.

.2）BSA (Bovine Serum Albumin)， That is, bovine serum albumin, which belongs to the most stable and soluble albumin.

It has approximately 30-35 major amino groups that can be used for conjugation reactions with linkers, making BSA a popular carrier protein for weak antigen compounds. The disadvantage of BSA is that in many experiments, it is used as a blocking agent. If the peptide BSA conjugate serum is used for such detection and analysis, false positives usually occur because these sera contain antibodies against BSA.

.3）OVA (Ovalbumin)， That is, chicken egg white protein.

It can serve as a second carrier protein to verify whether antibodies specifically target only peptides rather than carrier proteins (such as BSA).

Peptide KLH coupling modification

KLH couples peptides through N-terminal NH2

KLH couples peptides through C-terminal COOH

KLH is a thiol conjugated peptide through Cys

Peptide BSA coupling modification

BSA couples peptides via N-terminal NH2

BSA couples peptides via C-terminal COOH

BSA is conjugated to cysteine peptides through Cys

Peptide OVA coupling modification

OVA is conjugated with N-terminal NH2 peptide

OVA 

Conjugated peptides via C-terminal COOH

OVA 

Thiol conjugated peptides via Cys

Peptide synthesis | Peptide customization - peptide KLH, BSA, OVA coupling services:

Cys Asn Lys Ile Lys Arg Arg His Val Ile Lys Pro coupled with KLH via Cys coupling

Asn Lys Ile Lys Arg Arg His Val Ile Lys Pro is Carboxylated with BSA