In recent years the Li Research Group and others have made significant advancements in the area of purification chemistry, focusing specifically on avoiding column chromatography and recrystallization.
This research and concept have been defined as Group-Assisted Purification (GAP) chemistry/technology as follows: “a chemistry for organic synthesis that avoids traditional purification methods such as chromatography and/or recrystallization by purposefully introducing a well-functionalized group in the starting material or in the newly generated product.”
Research grade peptides will be shipped lyophilized in small polypropylene vials (2 ml or 10ml) with screw caps. Shipment packing material includes freezer packs and protective padding to avoid damage to the product while in transit. All product tubes contain labels with information on primary sequence, amount, and batch number. We provide all customers with a detailed Certificate of Analysis (CoA) which includes MALDI-TOF and/or ESI HRMS to confirm identity of the product delivered.
In most cases, GAP-PS research and production is defined under an MSA and SOW. The potential upsides of research include discovery of new pathways for using GAPP’s technology to deliver high peptide yields and easy scale up; flexibility in protecting group strategies; utilizing green chemistry and lowering solvent waste; and delivering high crude-purity peptides which may result in reduction of column time and reduction of overall peptide synthesis cost. Research can be unpredictable but research timelines can be shortened if the client provides known literature or procedures for their existing synthetic routes.
The synthesis of peptides using Group Assisted Purification Peptide Synthesis (GAPPS) resembles solid-phase peptide synthesis, but our process runs in solution. By running the coupling reaction in solution phase and purifying by simple filtration and/or extraction, GAP Peptide Synthesis combines the advantages of both LPPS and SPPS techniques. Purification for the process is facilitated by a small anchor molecule which controls solubility during an aqueous liquid extraction process. The uniquely designed anchor molecule replaces resin beads used in solid-phase peptide synthesis (SPPS). GAPPS uses standard Fmoc amino acid derivatives found in SPPS. Coupling and deprotection of the Fmoc protecting groups are performed in solution and allow for fast cycle times and direct in-process controls. Excess reagents as well as reaction related by-products are removed by aqueous extractions. Intermediate isolation of the protected peptide and excessive washing steps are not required when using the GAPPS approach. The process requires no special equipment.
GAP Peptide Synthesis is highly amenable to Fmoc chemistry, but it can also handle Cbz and Boc protection strategies. Because our proprietary GAP Groups function chemically as just another protecting group, all chemistries are amenable to our method. This includes carbodiimide, uronium, ammonium, and other coupling reagents, including Oxyma based products.
Currently, the technology is proven for shorter peptides (used predominately in Cosmetics) – and our research is progressing towards demonstrating the approach on Pharma-length peptides. GAPPS addresses the key challenges manufacturers are facing – lowering CoGS, controlling quality, improving the environmental impact. GAPPS offers easy scalability, high process efficiency, and greener manufacturing. Solvent consumption and material requirements are significantly reduced compared to legacy methods. GAPPS also avoids the use of solvents and reagents which are carcinogenic, mutagenic, or toxic to reproduction (CMR substances).
GAP Peptides can provide a variety of well-established peptide modifications like acetylation, biotinylation, phosphorylation, and attachment of fluorescent dyes or quencher pairs. We also provide synthesis services for unusual reactions. To discuss special needs in detail – please call or email for more information.
GAP Peptides, LLC currently has in-house capacity to synthesize custom peptides from the g to hundreds-of-grams scale. Providing mg scale is also possible for sample purposes. Process advantages and tangible benefits delivered increase at larger scales; contact us to discuss synthesis of larger volumes.
GAP Peptides offers different purity levels starting with >80% up to >99%.
The following list might serve as guideline for peptide purity specification:
- 75%: immunological applications, epitope discovery, and nonsensitive screening;
- 85%: immunological applications and epitope validation;
- 95%: SAR studies and immune monitoring assays;
- 96%: NMR, crystallization, and enzymatic assays;
- 98%: NMR, crystallization, and sensitive bioassays.
GAP Peptides currently offers custom research services for peptides ranging from two to twenty-two amino acids in length. Recent research progress has shown our process enables efficient production of most of the peptides in range from three to eighteen amino acids in length; however, ongoing research aims to target peptide chains ranging up to thirty-two amino acids and beyond.
For longer peptides the synthesis efficiency success rate drops; therefore in the case of research conducted on longer length targets, recombinant technologies might be used depending on peptide application.
Custom research peptides made by GAP Peptides will be analyzed by HPLC and MS. In addition to MALDI-MS, our routine quality control testing includes HPLC-MS techniques to guarantee that a single peak is visible in the HPLC profile corresponding to the target mass.
Since peptides show different ion response depending on the actual primary sequence, availability of different MS-equipment is crucial for quality-assured analysis. We use state of the art equipment [MALDI-MS, HPLC-(ESI)MS (ion trap and quadrupole)] which guarantees unambiguous analysis and a reliable product.
A Certificate of Analysis (CoA), and other analytical data as requested and produced during the research effort, accompanies each peptide order shipped.
Our lab is located in Lubbock, TX, USA. We are near the campus of Texas Tech University (TTU) and the TTU Health Science Center (HSC). We are housed in the Innovation Hub which is a 40,000 square foot, LEED certified facility. Our location provides access to TTUs powerful analytical tools which include 5 high-field NMR spectrometers and multiple options for UHPLC and HRMS analysis.