TITLE:
Spin nature of genetic code
AUTHORS:
Alexander A. Tulub, Vassily E. Stefanov
KEYWORDS:
Spintronics; Nucleotides; Genetic Code; Quantum Computations; Berry’s Phase; Hyperfine Coupling
JOURNAL NAME:
Journal of Biophysical Chemistry,
Vol.4 No.2,
May
24,
2013
ABSTRACT:
Nature has
developed codon as a tool to manipulate a two-electron spin symmetry
(short-living electrons, forming a radical pair, arise from the Mg-bound
nucleosidetriphosphate cleavage at the triplet/singlet (T/S) crossing), which
permits or forbids further nucleotide synthesis (DNA/RNA) and the synthesis of proteins. The thesis is
confirmed by conducting DFT:B3LYP (6-311G** basis set) computations (T/S potential energy surfaces) with the model
system composed of the template (C-G-C-G-A
nucleotide sequence) and the growing chain (G-C-G nucleotide sequence,
DNA or RNA). The origin of codon is in hyperfine interaction between a single
electron, transferred onto the template, and three 31P nuclei
built into the phosphorus fragments of nucleotides. The nuclei, together with
the polynucleotide structure, form a spiral twist that is homeomorphic to a
triangle patch on the Poincare sphere. Each triangle has unique angle values
depending on the nucleotide nature and their position in the codon. The patch
tracing produces the Berry phase changing the electron spin orientation from “up” to “down”. The Berry phase accumulation proceeds around the (T/S)
conical intersections (CIs). The CIs are a
result of complementary recognition between nucleotide bases at
distances exceeding the commonly accepted Watson-Crick pairing by 0.17 A. Upon
changing spin symmetry, the DNA or RNA chain is allowed to elongate by
attaching a newly coming nucleotide. Without complementary recognition between
the bases, the chain stops its elongation. The Berry phase accumulation along
the patch tracing explains the effect of
Crick’s wobbling when the second nucleotide plays a primary role in
recognition. The data is directly linked to creation
of a quantum computing device.