title: Single-molecule sensing of caspase activation in live cells via plasmon coupling nanotechnology.
abstract: Apoptotic caspases execute programmed cell death, where low levels of caspase activity are linked to cancer (Kasibhatla & Tseng, 2003). Chemotherapies utilize induction of apoptosis as a key mechanism for cancer treatment, where caspase-3 is a major player involved in dismantling these aberrant cells. The ability to sensitively measure the initial caspase-3 cleavage events during apoptosis is important for understanding the initiation of this complex cellular process; however, current ensemble methods are not sensitive enough to measure single cleavage events in cells. To overcome this, we describe a procedure to develop peptide-linked gold nanoparticles that have unique optical properties and can serve as beacons to visualize the apoptotic drug response in cancer cells at the single-molecule level. By thorough analyses of their trajectories, one can reveal early-stage caspase-3 activation in live cells continuously and with no ambiguity.
authors: Department of Pharmaceutical Chemistry, University of California, San Francisco, California, USA; Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, California, USA.
authors: Cheryl
authors: C
authors: Tajon
authors: Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, California, USA; Department of Otolaryngology, University of California, San Francisco, California, USA.
authors: Young-Wook
authors: YW
authors: Jun
authors: Department of Pharmaceutical Chemistry, University of California, San Francisco, California, USA; Graduate Program in Chemistry and Chemical Biology, University of California, San Francisco, California, USA. Electronic address: charles.craik@ucsf.edu.
authors: Charles S
authors: CS
authors: Craik
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D017209:Apoptosis; D015374:Biosensing Techniques / Q000295:instrumentation*; D053148:Caspase 3 / Q000378:metabolism*; D002470:Cell Survival; D003110:Colonic Neoplasms / Q000201:enzymology; D004789:Enzyme Activation; D057075:Enzyme Assays / Q000295:instrumentation; D004867:Equipment Design; D006046:Gold / Q000737:chemistry / Q000378:metabolism*; D006801:Humans; D008853:Microscopy / Q000295:instrumentation; D008969:Molecular Sequence Data; D053758:Nanoparticles / Q000737:chemistry / Q000378:metabolism* / Q000648:ultrastructure; D036103:Nanotechnology / Q000295:instrumentation*; D010455:Peptides / Q000737:chemistry / Q000378:metabolism*
chemical_list: D010455:Peptides; D006046:Gold; D053148:Caspase 3
keywords: Caspase; Gold nanoparticles; Live cells; Plasmon coupling; Single molecule