In a paper I am reading regarding instability and decay of DNA, the author says:
"The chemical price paid for the greatly increased resistance of the nucleic acid phosphodiester bond (gained by removal of the sugar 2'-OH group) is the labile N-glycosyl bond"
I am trying to understand the link between the two chemical bonds. Are they dependent on each other (e.g. one causes the other?)
I am trying to understand the link between the two chemical bonds. Are they dependent on each other (e.g. one causes the other?)
One does not "cause" the other. Instead, the author is only trying to say that removing the 2' hydroxyl group from nucleotides does two things: (a) vastly increases stability of 3' bond to phosphate, and (b) decreases the stability of the N-glycosyl bond. There's no way to get just one effect without the other, since you can either have a 2'-OH group or not.
A source to look for more information on N-glycosidic bond stability is the work of Richard Wolfenden. The linked paper shows that in 2'-deoxynucleosides, the N-glycosidic bond has a half-life at 37 °C of between 12 and 43 years. (That is the water-catalyzed half-life. Of course hydrolysis in strong base, strong acid, or by enzymes accelerates this rate, but the "un"catalyzed or merely water-catalyzed rate is of most interest as an indicator of bond stability.)
A later paper also by Wolfenden et al. directly compares the stability of the N-glycosidic bond of adenosine to 2'-deoxyadenosine and finds large differences. At 25 °C, the half-life of adenosine's N-glycosidic bond was 6000 years, while that for deoxyadenosine was only 180 years. (Note the difference in temperature between this paragraph and the preceeding.)
Those papers help indicate the instability of N-glycosidic bond in 2'-deoxysugars. Yet another Wolfenden paper examines the stability of phosphodiester bonds, although because of experimental difficulties there was no direct comparison between say A-A and dA-dA hydrolysis rates.
