Ultra-Efficient Solid Phase Peptide Synthesis (UE-SPPS)

CEM at Ultra-Efficient Solid Phase Peptide Synthesis (UE-SPPS) Ultra-Efficient Solid Phase Peptide Synthesis (UE-SPPS) is a revolutionary approach to peptide production, completely eliminating the resin washing steps required in more traditional approaches to solid phase peptide synthesis. Complete wash elimination is achieved by a combination of in-situ quenching of excess activated amino acid monomers and controlled evaporation of excess deprotection base. All reactions (couplings and deprotections) are enhanced through optimized microwave irradiation, facilitating high quality syntheses of peptides and proteins (even those up to 100 amino acids in length). Through this, UE-SPPS eliminates up to 95% of the total waste produced in typical SPPS methodology. A paper discussing this development was recently published in Nature Communications. You can find the full article here.

UE-SPPS is a groundbreaking advancement for peptide synthesis and available on CEM's Liberty Blue 2.0 and Liberty PRIME 2.0 systems. Explore the benefit and technology behind UE-SPPS below:

Exceptional Purity

Headspace Gas Flushing1
Headspace Gas Flushing
  1. Microwave heat drives Fmoc-deprotection to completion.
  2. Nitrogen (N₂) gas flows into the reaction vessel.
  3. Deprotection base evaporates via microwave heating.
  4. Nitrogen (N₂) + deprotection base flows out of the reaction vessel to waste.
  5. Remaining reagents and side products filter to waste.
Simply put, a cleaner reaction environment facilitates cleaner synthesis outcome.
CEM's patented Headspace Gas Flushing technology removes volatile deprotection base from the reaction headspace before condensation can occur on upper vessel surfaces. Base condensation and (often inopportune) reaction solution reentry can heavily impact synthesis purity, especially in longer sequences where even small impurity products can quickly accumulate.

Complete evacuation of the deprotection base from both the reaction solution and headspace has an additional advantage: elimination of extensive and repetitive vessel washing steps. Continue reading for more information on efficiency benefits.

Headspace Gas Flushing
JR 10-mer

CarboMAX Coupling2
When synthesis purity matters, so does your coupling strategy.
Carbodiimide-promoted coupling methodologies offer a host of advantages over onium salt-promoted coupling (e.g. HBTU/DIEA) approaches, especially at elevated temperature. Benefits of carbodiimide methodology include both drastically lower enolization/ epimerization rates and elimination of other base-catalyzed side reaction occurrences.

CarboMAX Coupling
R = Amino Acid Side Chain
Y = Side Chain Protecting Group
A = OH, NH

CarboMAX™ is a further enhancement to standard carbodiimide methodology for peptide coupling. Developed at CEM, CarboMAX routinely enables higher coupling efficiency and lower epimerization rates than even standard carbodiimide methodologies. Learn more here.

Crude Purity
Peptide Sequence Standard CarboMAX
Thymosin SDAAVDTSSEITTKDLKEKKEVVEEAEN 63% 75%
GRP GRPVPLPAGGGTVLTKMYPRGNHWAVGHLM 62% 74%
Bivalirudin fPRPGGGGNGDFEEIPEEYL 80% 82%
1-34PTH SVSEIQLMHNLGKHLNSMERVEWLRKKLQDVHNF 67% 85%
35-55MOG MEVGWYRSPFSRVVHLYRNGK 77% 91%
Magainin 1 GIGKFLHSAGKFGKAFVGEIMKS 71% 79%
Dynorphin A YGGFLRRIRPKLKWDNQ 74% 82%
Liraglutide* HAEGTFTSDVSSYLEGQAAK(γ-Glu-palmitoyl)EFIAWLVRGRG-OH 74% 88%
*Synthesized with ~ 0.32 mmol/g Fmoc-Gly-Wang PS resin

Microwave Energy3
CEM - Microwave Energy

Better reaction conversion, every step of the way.
Microwave irradiation is a well-established technology for enhancing the purity of peptides made via solid phase peptide synthesis and has been described in hundreds of publications worldwide. A global pioneer in microwave SPPS, CEM introduced the world's first automated microwave peptide synthesizer in 2003.

Unmatched Efficiency

Incredible Waste Reduction
Reduce waste production, not synthetic yield/purity.
By employing carbodiimide-promoted coupling methodology, the UE-SPPS process eliminates post-coupling wash step requirements. Any residual activated amino acid from coupling is quenched by the subsequently added deprotection base before any side reactions can occur.

Expanding upon this principle, UE-SPPS utilizes a “one-pot” coupling and deprotection step where a small amount of deprotection solution is added to the existing coupling solution, reducing the combined solvent needs for the two reactions by almost 50%. (I.e. The solvent from the coupling step is reused in the following deprotection step.)
Traditional SPPS Cycle (Extensive Wash Related Waste)
UE-SPPS Cycle (No Wash Related Waste)
Through development of the Headspace Gas Flushing technology (the evaporative-based process described above), UE-SPPS also eliminates post-deprotection wash step requirements. The volatile deprotection base (pyrrolidine) is rapidly evaporated from the vessel at temperatures > 90 °C simultaneous to a rapid microwave assisted deblocking step. Flushing of the headspace gas prevents volatilized deprotection base from condensing on the upper surfaces of the reaction vessel. Together, these processes render the peptidyl resin ready for the next coupling reaction, sans washing.

Through a remarkable combination of methodology optimization, reagent selection, and engineering advancements, UE-SPPS reduces waste production by up to 95%, and all without sacrificing synthesis yield and purity.

Traditional SPPS UE-SPPS
Waste per AA addition* 100 mL < 5 mL
Waste per 10-mer* 1 L < 50 mL
*@ 0.1mmol
Undeniable Time Savings
Quicker synthesis turnaround times facilitate more nimble research and exploration initiatives.
UE-SPPS is not only efficient in terms of waste production, but also time requirements. Through the same strategic combination of methodology optimization, reagent selection, and engineering advancements detailed above, UE-SPPS reduces synthesis time by up to 95% as well.

Traditional SPPS UE-SPPS
Time per AA addition* 2 hours < 4 minutes
Time per 10-mer* 20 hours < 40 minutes
*@ 0.1mmol