Lack of Z-DNA Conformation in Mitomycin-Modified Polynucleotides Having Inverted Circular Dichroism

Poly(dG-dC)· poly(dG-dC) and Micrococcus lysodeikticus DNA were modified by exposure to reductively activated mitomycin C, an antitumor antibiotic. The resulting covalent drug-polynucleotide complexes displayed varying degrees of CD inversions, which are strikingly similar to the inverted spectrum observed with Z-DNA. The following criteria have been used to establish, however, that the inverted CD pattern seen in mitomycin C-polynucleotide complexes does not reflect a Z-DNA conformation. (i) The ethanol-induced transition of poly(dG-dC)· poly(dG-dC) from B to Z conformation is not facilitated but rather is inhibited by mitomycin C modification. This may be due to the presence of crosslinks. (ii) Radioimmunoassay indicated no competition for Z-DNA-specific antibody by any of the mitomycin C-modified polynucleotides. (iii) 31P NMR of the complexes yielded a single relatively narrow resonance, which is inconsistent with the dinucleotide repeat characteristic of Z-DNA. Alternative explanations for the inverted CD pattern include a drug-induced left-handed but non-Z conformational change or the superposition of an induced CD onto the CD of B-DNA due to drug-base electronic interactions. These results illustrate the need for caution in interpreting CD changes alone as an indication of Z-DNA conformation

Toward a client-centered benchmark for self-sufficiency: Evaluating the ‘process’ of becoming job ready.

The purpose of this study is to evaluate how service providers, clients, and graduates of a job training program define the term self-sufficiency (SS). This community-engaged, mixed method study qualitatively analyzes focus group data from each group and quantitatively examines survey data obtained from participants of the program. Findings reveal that psychological transformation as a ‘process’ represents the emic definition of SS—psychological SS—but each dimension of the concept is reflected in varying degrees by group. Provider and participant views are vastly different from the outcome-driven policy and funder definitions. Implications for benchmarking psychological SS as an empowerment-based ‘process’ measure of job readiness in workforce development evaluation are discussed