Sample Abstracts from Last Year’s Qualification Model
Two abstracts from last year’s qualification model have been provided to help guide the team in the
abstract writing process. The first abstract highlights the major components for inclusion in an abstract.
You may want to provide your SMART Team practice in identifying these components on the second
abstract.
Saint Dominic School SMART Team
Jacob Austin, Grace Gundrum, Grace Hilbert, Claire Hildebrand, Brigid Hughes, Sophia Jaskolski, Michael
Kahler,William Klingsporn, Deidre Lagore, Katherine MacDonald, Tyler Mark,
Jackson Minessale, Sean O'Brien, Matthew Peterman, Sam Reinbold, Alex Rusnak, Alex Sands,
Lydia Scott, Rachel Storts, Mia Vuckovich, Michael Weisse, Nicholas (Mac) Wilke, Cade Wormington
Teacher: Donna LaFlamme
Ricin
Comment [GRV1]: School and Team Member
Names
Comment [GRV2]: Advisor’s Name
Comment [GRV3]: Title
PDB: 2AAI
Comment [GRV4]: PDB File
Primary Citation: Rutenber, E., Katzin,B.J., Ernst, S., Collins, ElJ., Mlsna, D., Read, M.P., Robertus, J.D. (1991).
Crystallographic refinement of ricin to 2.5 A. Proteins 10: 240-250.
Comment [GRV5]: Primary Citation
Abstract:
In 1978, Bulgarian journalist and critic of communism, Georgi Markov, was assassinated on a London street by a
probable KGB spy, who injected him with 0.2 mg of ricin, the lethal dose being less than 0.010 mg/kg. Ricin, a
ribosome inactivating protein, can be extracted from the seeds of the castor oil plant (Risinus communis) where it
functions as an insecticide. The Saint Dominic SMART Team modeled the heterodimeric protein ricin using 3D printing
technology. Chain B of ricin binds to terminal galactose residues on cell surface glycoproteins and glycolipids of
mammalian cells, facilitating ricin’s entry by endocytosis. The toxin then navigates a complex system of cytoplasmic
membranes from early/late endosomes, to the trans-Golgi network, to the endoplasmic reticulum (ER). In the ER
lumen, translocases are thought to move the toxin into the cytosol but it is not known if Chain A is activated by
cleavage from Chain B before or after translocation. Once in the cytosol, Chain A irreversibly disables ribosomes by
removing adenine 4324 from the 28S RNA strand of the large subunit. To do this, active site residues Tyr80 and
Tyr123 are thought to stabilize A4324, while Arg180 and Glu177 hydrolyze the glycosidic bond attaching it to the
sugar-phosphate RNA backbone. A4324 belongs to the highly conserved sarcin-ricin loop and its removal shuts down
protein synthesis by preventing elongation factor binding. An intracellular terrorist capable of disabling 1500
ribosomes/minute, one molecule of ricin can kill a cell. Researchers are now developing immunotoxins incorporating
ricin to target and assassinate cancer cells rather than people.
Comment [GRV6]: “Big Picture” or “Hook”
Statement
Comment [GRV7]: Modeling Project Statement
Comment [GRV8]: Structure/Function
Description
Comment [GRV9]: Tie to the opening “big
picture” and description of “next steps”
Sample Abstracts from Last Year’s Qualification Model
Marquette University High School SMART Team
J. Fuller, D. Kim, R. Sung, E. Arnold, A. Borden, L. Ortega, R. Johnson, H. Albornoz-Williams,
C. Gummin, A. Martinez, N. Boldt, D. Ogunkunle, P. Ahn, B. Kasten, Q. Furumo, N. Yorke,
J. McBride, I. Mullooly, M. Tripi, D. Hutt.
Teachers: Keith Klestinski and Carl Kaiser
Ricin—A Deadly Legume Extract
PDB: 2AAI
Primary Citation: Rutenber, E., Katzin,B.J., Ernst, S., Collins, ElJ., Mlsna, D., Read, M.P.,
Robertus, J.D. (1991). Crystallographic refinement of ricin to 2.5 A. Proteins 10: 240-250.
Abstract:
One of the most deadly toxins ever discovered comes from the waste of castor bean oil
processing. The toxin, ricin, has been responsible for the deaths and attempted attacks of
world leaders. Ricin is a protein molecule with two major chains—chain A and chain B. Chain
A, acts as an enzymatic polypeptide that catalyzes the N-glycosidic cleavage of a specific
adenine residue from 28S ribosomal RNA. The amino acids in the active site responsible for
this action are Glu 177, Arg 180, Tyr 80, Tyr 123, Glu 177, Arg 180, and Trp 211. With help from
chain B, the ricin binds to mammalian cell surfaces. A disulfide bond breaks between the two
chains allowing only chain A to enter into the cell via endocytosis. Once in the cell, it delivers
the catalytically active polypeptide into the cytosol where it irreversibly inhibits translational
elongation, an important aspect of protein synthesis, at a rate of 1500 ribosomes per minute.
Researchers are working to develop an immunotoxin that combines the targeting ability of an
antibody with the toxicity of the ricin A chain. These antibodies are directed exclusively toward
cancer cells to deliver a “lethal blow” ultimately destroying the cells. Cancer cell targeting and
ricin’s unique ability to cleave important parts of ribosomes will be of continued interest in
oncology research. In order to show the detailed complexities of the protein, the Marquette
University High School SMART (Students Modeling A Research Topic) Team has modeled ricin
using 3D printing technology.