What is Peptide Purity?

In KMD Bioscience's product catalog, the purity of synthetic peptides typically ranges from 90% to 95%, with the highest purity reaching 99%. In the lyophilized powder shipped to customers, 95% of the NET PEPTIDE content (not total peptide content) consists of the customer's target peptide. The remaining 5% of peptide material in the sample generally comprises peptides with missing amino acids. These incomplete peptides result from slightly inefficient coupling reactions during synthesis, where certain amino acids in the peptide sequence were skipped. Purity is typically determined by reverse-phase HPLC analysis.

How pure does my peptide need to be?

Methods for purifying peptides?

Answer: HPLC is used for purification.

How to store peptides?

Answer: Lyophilized peptides can be stored long-term at -20°C. For short-term storage, you may keep them at 4°C.

What is the best way to dissolve peptides?

Answer:

-- Sonication can enhance solubility.

-- 10% acetic acid in the solvent helps dissolve basic peptides.

-- 10% ammonium bicarbonate aids in dissolving acidic peptides.

--For peptides with extremely low solubility in aqueous solutions, an organic solvent (e.g., DMSO, isopropanol, methanol, or acetonitrile) should be used first. Once the peptide is fully dissolved, water can be gradually added until the desired concentration is achieved.

What are counterions?

Answer: Most peptides exist in their salt form, except those lacking basic amino acids (such as Arg, Lys, His, or those with blocked N-termini). Synthetic peptides purified by HPLC are typically obtained as TFA salts. In these peptides, the basic amino acid residues and N-terminus are protonated and carry trifluoroacetate (CF3COO⁻) counterions.

What is the maximum peptide length that can be produced?

Answer: KMD Bioscience can synthesize peptides up to 200 amino acids (AA) in length. Peptides of 50-70 AA can be obtained through direct chemical synthesis. Longer peptides can be produced by chemically ligating several synthetic peptide fragments.

What is the direction of peptide synthesis?

Answer: Peptides are synthesized from the C-terminus to the N-terminus of the sequence.

Can you provide cGMP-grade peptides?

Answer: KMD Bioscience offers large-scale cGMP peptide services, with a capacity of up to 2 kg per project.

Do you have any requirements for phosphopeptide design?

Answer: We recommend placing the phosphorylated residue within 10 amino acids from the N-terminus, as the coupling efficiency of residues following the phosphorylated site can decrease significantly.

Are there any requirements for introducing dye modifications?

Answer: We recommend adding a spacer between the peptide and the dye molecule. This helps minimize the dye's interference with peptide folding and receptor binding. However, if the purpose of dye labeling is to quantify fluorescence transfer between different structural intervals, a spacer should not be introduced.

What are the benefits of capping the N- and C-termini of a peptide?

Answer: Capping makes the peptide resemble natural proteins more closely. The N-terminus can be capped with an acetyl group, while the C-terminus can be capped with an amide group.

What are the advantages of peptide PEGylation?

Answer: PEGylation involves the covalent attachment of poly(ethylene glycol) (PEG) polymers to target molecules. It effectively enhances the therapeutic properties of peptides by shielding them from the host's immune system, increasing their solubility (especially for hydrophobic drugs), and improving bioavailability. Additionally, PEGylation can prolong the peptide's circulation time in the host by reducing renal clearance.

KMD Bioscience possesses advanced technology and extensive expertise in the field of peptide synthesis, offering comprehensive peptide synthesis and customization services. Our services cover a wide range of peptide sequences, from simple to highly complex, including but not limited to linear peptides, cyclic peptides, long-chain peptides, and peptides with special modifications (such as phosphorylation, methylation, acetylation, etc.). We employ Solid-Phase Peptide Synthesis (SPPS) combined with Liquid-Phase Peptide Synthesis (LPPS) to ensure high purity and bioactivity of the synthesized peptides.We provide customers with one-stop services, from sequence design and synthesis strategy optimization to final product purification and detailed quality analysis. Each step undergoes strict quality control, including Mass Spectrometry (MS) and High-Performance Liquid Chromatography (HPLC) analysis, to guarantee that the peptide products meet specific customer requirements. Additionally, we offer personalized services, delivering tailored solutions based on clients' unique application needs, such as bioactivity studies, drug development, vaccine research, and more.Leveraging our professional knowledge and services, KMD Bioscience is committed to becoming a trusted partner in peptide synthesis and applications for scientific research and the biotechnology industry. We strive to support our clients in achieving their research goals and accelerating the drug development process.