MEMBRANES BY DESIGN
with shorter fatty acid chain PROTOLIFE lengths and larger head Artist’s rendition of a primitive cell, groups—improved the percomposed of a fatty acid-based membrane meability of their synthetic and containing replicating nucleotides. membranes. By adding lipids with these properties— such as glycerol monodecanoate—to a mixture of amphiphiles, they made membranes that were more permeable to ribose, the sugar component of RNA, as well as to nucleotides. Szostak’s group then encapsulated a synthetic DNA molecule in their primitive membranes. They had previously found that this particular DNA, if given access to activated nucleotides, could guide production of complementary DNA without enzymes. Sure enough, the synthetic membrane let nucleotides in where they assembled into the complementary DNA product, which then remained in the primitive cell. “This work beautifully weaves together two of the central themes of life’s origins: the emergence of replicable genetic polymers and the advantage of compartmentalization in sequestering the fruits of metabolic labor,” says Gerald F. Joyce of the Scripps Research Institute, who studies self-replicating RNA. Despite having demonstrated a specific DNA-copying reaction, Szostak notes that “the chemistry of nucleic acid replicaO tion is the remaining hard part” of making a fully synthetic cell. He and O his coworkers are now working on OH making the nucleotide chemistry used in the current study more genGlycerol monodecanoate erally applicable.—CARMEN DRAHL
SYNTHETIC BIOLOGY: Permeable
barrier is step toward building cells from scratch
T
HE ADVENT OF synthetic life may have gotten
a bit closer. Biochemist Jack W. Szostak and colleagues at Massachusetts General Hospital have designed a fatty acid container that takes in building blocks from outside to supply a spontaneous DNAcopying reaction on the inside (Nature, DOI: 10.1038/ nature07018). The synthetic biology advance, Szostak says, suggests a way by which primitive cells could have obtained nutrients, a key unknown in the origin-of-life field. It’s not clear whether the earliest cells made their own components or incorporated them from outside, he says. Modern cell membranes are barricades that require protein pumps and pores for shuttling nutrients in and out. But early membranes might not have behaved in the same way, Szostak says. His team has now used a mixture of fatty acids, fatty alcohols, and esters to make a synthetic barrier that is more permeable to sugars and nucleotides than today’s biological membranes. “Our experiments show that primitive cells may well have been able to absorb nutrients from their environment,” he says. The team formed membranes with optimized mixtures of amphiphiles, molecules with polar heads and nonpolar tails. These membranes allow small molecules to enter the volume they enclose but don’t permit polymers inside to leak out. The researchers found that modified versions of conventional membrane components—such as lipids
APPOINTMENT Yale provost, chemist Andrew Hamilton, to be vice chancellor at Oxford one of the great centers of learning and research.” In the U.K., a vice chancellor is the senior administrator of a university, equivalent to a university president in the U.S. Hamilton is scheduled to take up the new post in October 2009. He will be responsible for providing strategic direction to Oxford, as well as representing the university nationally and internationally. Hamilton, 55, was born in Guildford, England, and reM I C H A E L M A RS L A N D/ YA L E
Oxford University has recruited chemist Andrew Hamilton, who is currently provost at Yale University, to be its next vice chancellor. Hamilton’s nomination is subject only to the expected approval by Oxford’s parliament of dons, the British institution’s legislative body. “I am very excited and honored to be nominated as the next vice chancellor of Oxford University,” Hamilton tells C&EN. “It is the oldest university in the English-speaking world and has always been Hamilton
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ceived his Ph.D. from Cambridge University in 1980. He has received numerous awards, including the ACS Arthur C. Cope Award. While he was provost at Yale, Hamilton maintained an active research program in molecular recognition. He says he intends to do the same at Oxford. “I have found that staying involved with research as an administrator is not only good for my sanity, but also allows me to stay connected to students and faculty and to appreciate the pressures of funding, compliance, and other demands of the modern scientific world.” —SARAH EVERTS
JA N E T I WASA
N EWS O F T H E W E E K
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