Não podemos estender o alfabeto genético, pois o DNA é coisa de profissional.

Unintended Consequences of Expanding the Genetic Alphabet

Marvin Pollum†, Brennan Ashwood†, Steffen Jockusch‡, Minh Lam§, and Carlos E. Crespo-Hernández*†

† Department of Chemistry, Case Western Reserve University, Cleveland, Ohio 44106, United States

‡ Department of Chemistry, Columbia University, New York, New York 10027, United States

§ Department of Dermatology, Case Western Reserve School of Medicine, Cleveland, Ohio 44106, United States

J. Am. Chem. Soc., Article ASAP

DOI: 10.1021/jacs.6b06822

Publication Date (Web): August 26, 2016

Copyright © 2016 American Chemical Society

*carlos.crespo@case.edu

Abstract

The base pair d5SICS·dNaM was recently reported to incorporate and replicate in the DNA of a modified strain of Escherichia coli, thus making the world’s first stable semisynthetic organism. This newly expanded genetic alphabet may allow organisms to store considerably more information in order to translate proteins with unprecedented enzymatic activities. Importantly, however, there is currently no knowledge of the photochemical properties of d5SICS or dNaM—properties that are central to the chemical integrity of cellular DNA. In this contribution, it is shown that excitation of d5SICS or dNaM with near-visible light leads to efficient trapping of population in the nucleoside’s excited triplet state in high yield. Photoactivation of these long-lived, reactive states is shown to photosensitize cells, leading to the generation of reactive oxygen species and to a marked decrease in cell proliferation, thus warning scientists of the potential phototoxic side effects of expanding the genetic alphabet.

+++++

Professores, pesquisadores e alunos de universidade públicas e privadas co acesso ao Portal de Periódicos CAPES/MEC podem ler gratuitamente este artigo do Journal of the American Chemical Society e mais 30.000 publicações científicas.

+++++

A atual teoria geral da evolução - a SÍNTESE EVOLUTIVA AMPLIADA/ESTENDIDA não explica a origem da informação genética (complexa e especificada). O DNA é coisa de profissional. 

Há quase duas décadas a TDI propõe a informação complexa e especificada no DNA... E a TDI é pseudociência, cara-pálida???