NEWS OF THE WEEK
CLEANTECH FUNDING FALLS VENTURE CAPITAL: Weak start to second
half reflects economic concerns
A
FTER A STRONG first half, worldwide venture
capital investment in environmentally friendly firms hit a snag, falling 30% in the third quarter to $1.53 billion. The quarterto-quarter drop is likely due UNSEASONABLY COOL to investor concerns about Investment in cleantech dropped in the the slow economic recovthird quarter ery, according to Cleantech Total amount of deals, $ billions No. of deals Group, the research firm 200 3.0 that gathered the statistics. 2.5 In addition, funding for 150 2.0 cleantech companies was down 11% from the third 1.5 quarter of 2009. 100 1.0 However, the cleantech 0.5 industry continues to raise more venture money than 0.0 50 2005 2006 2007 2008 2009 2010 the biotech and information SOURCE: Cleantech Group technology sectors. Within cleantech, technologies re-
NEW WINDOW ON PHOSPHORYLATION PROTEIN CHEMISTRY: Structural
mimics provide a handle on tough-to-capture modification
O– O
P
N
O–
N N H3N+ O
O–
Phosphohistidine analog
F
OR THE FIRST TIME, stable analogs of phospho-
histidine have been used in peptide and protein synthesis and in antibody production. These analogs give researchers a new way to probe histidine phosphorylation, a common protein modification that helps control enzyme activity in cells. Phosphorylation is the addition of phosphates to hydroxyl groups on serine, threonine, and tyrosine residues and to imidazole nitrogens on histidine. But histidine phosphorylation “has been a bit of a blind spot for chemists and biochemists because of the intrinsic instability of the modification,” says Tom W. Muir, a professor at Rockefeller University and leader of the new study. Muir and postdoc Jung-Min Kee developed stable analogs of phosphohistidine that don’t hydrolyze or isomerize and used them to synthesize modified peptides and proteins (J. Am. Chem. Soc., DOI: 10.1021/ ja104393t). The phosphoryltriazolylalanine-based WWW.CEN-ONLINE.ORG
10
lated to transportation, biofuels, and the electric grid received the most money, but the largest number of deals was at firms focused on energy efficiency. Cleantech Group President Sheeraz Haji says energy-efficiency deals are attractive because they require small amounts of capital and offer fast payback times. Chinese firms snagged two of the top 10 cleantech investments; the larger was in eHi Car Service, a Shanghai-based car-sharing company, which raised $70 million. In North America, the two biggest funding rounds went to Texas-based Kior, a developer of catalytic technology for making so-called biocrude from biomass, and to Canadian waste-to-energy firm Plasco Energy. The start-ups each raised $110 million. The slow pace of the economic recovery made the season a difficult one for start-ups that want to access the capital markets. The third quarter saw only eight cleantech initial public offerings (IPOs), compared with 22 in the second quarter. A slow IPO market can hamper new investments by venture capitalists worried about returns. “Less than 10% of global cleantech venture investment dollars today are going into early-stage deals,” says Dallas Kachan of Kachan & Co., a cleantech analysis firm. “Investors are creating a disproportionate amount of ‘walking dead’—companies kept alive, sometimes bolstered by government funding, hoping for an exit,” Kachan says. “That’s capital that new cleantech innovation isn’t getting.”—MELODY VOITH
analogs mimic the geometry and electronics of phosphohistidine but replace the N–P bond of the natural amino acid with a nonhydrolyzable C–P bond. “That nitrogen-phosphorus bond is extremely labile,” Muir says. “It’s a liability in terms of biochemical analysis. It had to go.” Muir and Kee collaborated with Bryeanna Villani and Laura R. Carpenter of cell-biology firm Active Motif in Lake Placid, N.Y., to raise antibodies against peptides containing the analogs. “Prior to this study, there were no antibodies that specifically recognized phosphohistidine in any context,” Muir says. The new antibodies specifically recognize histone proteins with phosphorylated histidines but not their nonphosphorylated or nonhistidine phosphorylated counterparts. The antibodies will allow researchers to “address a series of critical issues regarding the evolution and function of protein histidine phosphorylation in mammalian systems that have languished in the literature for the past 25 years,” says Melvin I. Simon, an emeritus professor of biology at California Institute of Technology. The current antibodies recognize phosphohistidine only in the context of histone tail peptides, but Muir’s group is developing others that will recognize phosphohistidine in any context. “Such reagents would be incredibly powerful in proteomic studies for looking at broad occurrences of this modification,” Muir says.— CELIA ARNAUD
OCTOBER 11, 2010
