Premium
Calorimetric investigations of crystalline 3′,5′‐cyclic nucleotides
Author(s) -
Bryan A. M.,
Olafsson P. G.
Publication year - 1973
Publication title -
biopolymers
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.556
H-Index - 125
eISSN - 1097-0282
pISSN - 0006-3525
DOI - 10.1002/bip.1973.360120203
Subject(s) - chemistry , homolysis , crystallography , ring (chemistry) , nucleotide , cleavage (geology) , guanosine , stereochemistry , organic chemistry , radical , biochemistry , geotechnical engineering , fracture (geology) , engineering , gene
Differential enthalpic analysis of a series of 3′,5′‐cyclic nucleotides indicates that homolytic cleavage of the six‐membered phosphate ring occurs either immediately prior to or concurrent with decomposition of the crystal lattice. Homolysis is followed by a rapid polymerization to yield oligonucleotides. The enthalpies of these reactions have, with the exception of guanosine 3′,5′‐cyclic phosphate, almost identical values of 25 kcal/mole. The anomalous case is attributed to a more stabilized phosphate ring as a result of hydrogen bonding through the two position of the purine ring. The pair of overlapping exothermic peaks observed in each of the thermograms for cAMP and cIMP is related to the presence of two conformational arrangements within the unit cell of each compound.