Frank Zhang, Ph.D., CEO of GenScript, describes a growing market for research-grade peptides, especially for epitope-mapping applications in antibody drug discovery and for the production of peptide arrays for screening. Custom peptide synthesis is one facet of GenScript’s CRO business, which also includes gene synthesis and cloning services, antibody development, and protein expression and purification.
In October, GenScript launched a series of GMP-grade peptides for use as anti-aging ingredients in cosmeceuticals and dermaceuticals. These peptides contain various modifications intended to enhance skin-permeating and antiwrinkle properties; examples include acetyl hexapeptide-3, palmitoyl hexapeptide, palmitoyl tetrapeptide-3, palmitoyl pentapeptide, GHK-Cu2+, and PAL-GHK, which have been incorporated into the products of companies such as Replexion, Bioque, Urban Nutration, Avon, Osmotics, Newspirit, and Neova.
GenScript’s FlexPeptide™ synthesis platform integrates solid-phase synthesis, liquid-phase synthesis, microwave technology, and the company’s ligation technology. The company uses a combination of these synthesis tools, basing the selection of which methods to use on the properties of the peptide to be synthesized. For difficult synthesis steps, Dr. Zhang notes that the increased coupling rates enabled by microwave energy offer particular advantages. Microwave technology is also useful for introducing site-specific modifications.
“We do not only use machines,” says Dr. Zhang, “we may also use manual synthesis,” which allows for greater control over the process.
GenScript can synthesize peptide fragments up to 50 amino acids in length, producing batches from a few milligrams up to two kilograms, according to Dr. Zhang. The company’s ligation technology allows for the production of peptides up to 200 amino acids in length.
The demand for synthetic peptides for use in proteomic research applications continues to increase, enjoying a growth spurt that began a few years ago, according to Heinrich Gausepohl, Ph.D., director of development at Intavis Bioanalytical Instruments, a manufacturer of automated peptide synthesizers. Demand is particularly strong for small-scale peptide synthesis of large numbers of different peptides, with orders in the tens of thousands not uncommon. Dr. Gausepohl attributes the rising interest in isotope-labeled peptides to a growing number of mass spectrometry-based research projects.
Intavis’ MultiPep RS employs solid-phase Fmoc peptide synthesis to generate milligram quantities of up to 384 peptides in four 96-well filter plates. For larger-scale syntheses, an optional column module allows for production of up to 72 peptides in volumes ranging from 10 to 100 µmol.
The MultiPep RS can also perform automated SPOT synthesis to produce peptide arrays on a derivatized cellulose membrane. Recently, Intavis added a new capability, enabling the instrument to produce peptide microarrays on glass slides, with up to 384 peptides arrayed in duplicate on each slide.