Analysis of apoptosis in cell-free systems

DNA-instructed acyl transfer reactions for the synthesis of bioactive peptides

We present a method which allows for the translation of nucleic acid information into the output of molecules that interfere with disease-related protein-protein interactions. The method draws upon a nucleic acid-templated reaction, in which adjacent binding of reactive conjugates triggers the transfer of an aminoacyl or peptidyl group from a donating thioester-linked PNA-peptide hybrid to a peptide-PNA acceptor. We evaluated the influence of conjugate structures on reactivity and sequence specificity. The DNA-triggered peptide synthesis proceeded sequence specifically and showed catalytic turnover in template. The affinity of the formed peptide conjugates for the BIR3 domain of the X-linked inhibitor of apoptosis protein (XIAP) is discussed.

Granzymes in cancer and immunity

Cytotoxic T lymphocytes (CTLs) and natural killer (NK) cells are indispensable factors in the body's ongoing defence against viral infection and tumor development. CTL/NK cells recognize and kill infected or aberrant target cells by two major pathways: either through introduction of a battery of proteases - called granzymes - to the target cell cytosol, or through TNF superfamily-dependent killing. During granzyme-dependent killing, target cell death is quick and efficient and is mediated by multiple granzymes, acting via redundant cell death pathways. Although granzyme-mediated cell death has been intensively studied, recent work has also hinted at an alternative, proinflammatory role for these enzymes. Thus, in addition to their well-established role as intracellular effectors of target cell death, recent data suggest that granzymes may have an extracellular role in the propagation of immune signals. In this study, we discuss the role of granzymes as central factors in antitumor immunity, as well possible roles for these proteases as instigators of inflammation.