Sigma-Aldrich this week said it has expanded its protein-depletion and antibody product line by acquiring GenWay Biotech’s Seppro technology.
The transaction covers two separate but related products: the Seppro affinity-depletion technology and a library of 700 avian-derived antibodies.
Included in the deal are the current Seppro inventory, the production technology, and all future rights to produce and distribute the product lines, Sigma-Aldrich said in a statement.
Financial details were not disclosed.
For protein researchers, the wide dynamic range, particularly for blood, is a well-documented bottleneck in the search for clinically relevant biomarkers. A number of different commercially available technologies as well as research strategies exist to address this.
The Seppro depletion platform, built on chicken-derived IgY antibodies, is designed to process plasma, serum, and plant samples, and removes the 14 most-abundant proteins found in human serum and plasma: HGA; IgG; fibrinogen; transferrin; IgA; IgM; haptoglobin; alpha2-macroglubulin; alpah1-acid glycoprotein; alpha1-antitrypsin; apo A-1 HDL; apo A-II HDL; complement C3; and LDL (apoB).
The firm, which already had a protein-depletion line before the Seppro buy — its ProteoPrep product line — said customers can also use Seppro to deplete moderate-abundance proteins by using a column incorporating Seppro’s SuperMix technology.
The ability to use Seppro as a multiplexed tool for protein depletion in multiple steps is one attribute that Sigma hopes will distinguish the technology from rival depletion technologies, said George Lipscomb, global market segment manager for proteomics at Sigma-Aldrich.
“You can use multiple embodiments of the Seppro technology, so what people are doing in some cases is using a combination of one of the high-abundance depletions along with the SuperMix, which takes out another range of targets in the proteome,” he said. “By using those tools synergistically you achieve much better penetration.”
The SuperMix technology also enriches and amplifies low-abundance proteins, enabling researchers to detect them, Lipscomb added.
“Depending on what they want to achieve or the downstream analysis, they may be used synergistically or independently,” he said. “It’s very platform-dependent.”
“They want a different host, so they might want to do multiple-labeling and just need a different host. Chicken just fits the bill there.”
For example, in some instances a scientist may choose not to deplete at levels achievable with Seppro because “they have other multi-dimensional separation technologies that they’re using between the initial sample and the ultimate analysis,” he said. “Based on what those targets may be, they’ve chosen to deplete at varying levels, so the ProteoPrep [immunoaffinity albumin and IgG product] which depletes the two most abundant proteins may be the first step as opposed to a much deeper penetration.”
The purchase of the Seppro technology also allows Sigma-Aldrich for the first time to offer IgY antibodies. The new 700 IgY antibody library is derived from chicken embryos and prepared using recombinant antigens. Because chicken antibodies are more selective than mammalian proteins and have less cross-reactivity, they produce fewer false-positives in certain immunochemical assays, the company said.
The acquisition is the second significant expansion of Sigma’s antibody business over the past year, during which it has added 8,000 antibodies to its library. The company now sells more than 12,000 antibodies.
Last February, Sigma-Aldrich announced a partnership with Atlas Antibodies, the commercial arm of the Human Protein Atlas, to sell the firm’s highly characterized antibodies under the Prestige Antibodies name. That line now has more than 3,800 antibodies, Sigma said. [See PM 02/14/08]
The IgY antibodies aren’t as well-characterized as the Prestige line, said Leigh Gaskill, market segment manager for antibodies at Sigma-Aldrich. The IgY antibodies have been characterized mostly with ELISAs and Western blots, typical of most commercial antibodies, though some have some additional application testing, she said.
“These antibodies were not originally developed just for immunohistochemistry. They’re mostly developed for other applications,” though some work for immunohistochemistry, Gaskill said. “One of the interesting things is that some investigators are just looking for another host, so they may have an antibody that may work in rabbit. They want a different host, so they might want to do multiple-labeling and just need a different host. Chicken just fits the bill there.”
The company, she added, had not been specifically shopping for an IgY antibody line, but when the Seppro technology became available, it saw an opportunity to provide customers something it didn’t before.
“I think it’s pretty clear we’re interested in expanding our portfolio,” Gaskill said. “This is a full project. We were interested in Seppro products as well as the IgY antibodies just to increase our portfolio and to offer a slightly different product than the traditional antibodies that we’ve produced.”
In a written statement to ProteoMonitor, GenWay said that the products covered by the transaction comprised about 5 percent of its total catalog offering. It will continue to sell other antibodies, proteins, ELISA kits, and reagents, the company said.
“The divestiture of these operations enables GenWay to put more emphasis on its primary area of development and growth — diagnostic kits for research and clinical applications,” it added.