Searching for the Origins of Life
Could sulfur-based chemicals have formed the basis of life, if not on Earth, then perhaps on other planets?
"The big question is: Where did biological chemicals come from, and what are the boundaries for what constitutes biological chemicals?" asks Benjamin Rudshteyn (Macaulay Honors College at Brooklyn College, 2013), who won a 2012 Barry M. Goldwater Scholarship. This is the premier federally funded undergraduate scholarship to encourage study in the natural sciences, mathematics and engineering.
Congress established the highly competitive scholarship for U.S. sophomores and juniors, virtually all of whom intend to earn a PhD. No college can nominate more than four students, and only about 300 scholarships are awarded annually nationwide. The one- and two-year grants cover tuition, fees, books and room and board up to $7,500 a year. As a junior, Rudshteyn will get one year of support.
Rudshteyn's PhD will be in theoretical chemistry "or some variant of it." As for a career, he says, "I like teaching, I like research, so being an academic professor may be a good fit."
His undergraduate research is about as theoretical as it gets. "Reduced sulfur was in abundance in prebiotic Earth, but molecular oxygen was not," he says. "Oxygen initially was tied up in geological molecules, which had to be released to give birth to life as we know it. Sulfur-rich atmospheres exist on other planets and moons, like Jupiter's moon Io. That makes one wonder about whether life exists elsewhere, based on sulfur-based chemical reactions that occur in the extreme sulfur-rich conditions that existed when Earth was young."
Working with his Brooklyn College mentor, Chemistry Professor Alexander Greer, he ran computer simulations at the CUNY High Performance Computing Center at the College of Staten Island. The center makes state-of-the-art supercomputing resources and expert technical assistance available to faculty and students from throughout CUNY.
Rudshteyn's simulations produced hypothetical polydisulfide helices (spiral strands) that, he calculated, could be precursors to components resembling amino acids, the building blocks of life. This led to his principal-authorship of the article "Theoretical Study of a Nonpeptidic Polydisulfide Alpha-Helix" that will appear in the Journal of Sulfur Chemistry. The coauthors were PhD student Alvaro Castillo and Greer.
"I think, like Darwin, that life came randomly out of a pond when there were a lot of volatile gases and chemicals, and lightening came at the right moment to create amino acids," he says. "All the other biochemicals came from there."
Figuring out how chemicals give life on other planetary bodies requires 21st-century tools. "We can't get samples from prehistoric earth, except maybe from ice, and we can't get chemicals easily from other planets, so simulating on computers is what we can do," he says.
Rudshteyn also has been working on Greer's investigation of photodynamic therapy, an emerging technology for treating cancer. Some tumors can't be surgically removed or are placed where radiation would damage surrounding tissue. Photodynamic therapy, as the National Cancer Institute explains it, combines a drug called a photosensitizing agent with a specific wavelength of light from a laser or other source; perhaps delivered inside the body via a fiber optic cable, the light triggers production of an active form of oxygen that kills nearby cells.
"My job is to simulate the step where excited oxygen reacts with drug molecules and see if it would work," Rudshteyn says. "They're still working on the experimental side, but my computer work helps provide a proof of concept in a scaled-down version."
Rudshteyn was born in Brooklyn to a family who were trained as engineers (his mother in civil engineering, his father in mechanical engineering) in Belarus, when it was part of the Soviet Union. His father, Alex Rudshteyn, earned a master's degree in computer and information science at Brooklyn College in 1998 and is the college's associate director of Academic IT and Library Systems. His mother, Anna Rozenbaum, earned a master's degree in health and nutrition science at Brooklyn College in 1997 and works as a dietitian.