Abstract
The binding of spermine to the d(m5CGm5CGm5CG) duplex has been studied by proton and phosphorus nuclear magnetic resonance techniques in order to investigate the mobility and nature of spermine bound to the resulting Z-DNA complex. A characterization of the B to Z transition as a function of increasing spermine concentration demonstrated doubling of the non-exchangeable proton and the phosphorus peaks at a ratio of about 1:1 (spermine/duplex) and a re-simplification of the spectrum at 2:1 (spermine/duplex) where about 90% or the DNA was fully converted into the Z-form. However, some of the Z-DNA proton chemical shifts differed between the 1:1 and 2:1 titration points. Since these differences involved primarily the exchangeable terminal imino and amino protons, they could result from end effects. Discrepancies were generally not observed with the non-terminal proton shifts nor with the phosphorus shifts. These proton and phosphorus chemical shift changes are fully consistent with a, B to Z transition. Complexed spermine peaks appear about 0.1 parts per million upfield from the uncomplexed form. The spermine and both the B and Z-DNA hexamer signals are noticeably broadened at the 1:1 ratio but the remaining signals re-sharpen at the 2:1 ratio. Both one-dimensional and two-dimensional studies revealed negative nuclear Overhauser effect (NOE) contacts between each spermine proton. Therefore, spermine has a longer correlation time than that observed for unbounded spermine. These results are contrasted with the positive NOE contacts observed for the B-DNA-spermine complexes reported by Wemmer et al. using the dodecamer d(CGCGAATTCGCG)2 and reported here using the hexamer d(ATGCAT)2. While the mobility of spermine in the Z-DNA complex is significantly less than that of the B-DNA complex, no clear evidence of intermolecular spermine-DNA proton NOE contacts is observed.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 585-590 |
| Number of pages | 6 |
| Journal | Journal of Molecular Biology |
| Volume | 219 |
| Issue number | 4 |
| DOIs | |
| State | Published - Jun 20 1991 |
| Externally published | Yes |
Fingerprint
Keywords
- B-DNA
- negative NOE contacts
- proton n.m.r.
- spermine mobility
- Z-DNA
ASJC Scopus subject areas
- Virology
Cite this
1H and 31P nuclear magnetic resonance studies of spermine binding to the Z-DNA form of d(m5CGm5CGm5CG)2. Evidence for decreased spermine mobility. / Banville, Debra L.; Feuerstein, Burt G.F.; Shafer, Richard H.
In: Journal of Molecular Biology, Vol. 219, No. 4, 20.06.1991, p. 585-590.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - 1H and 31P nuclear magnetic resonance studies of spermine binding to the Z-DNA form of d(m5CGm5CGm5CG)2. Evidence for decreased spermine mobility
AU - Banville, Debra L.
AU - Feuerstein, Burt G.F.
AU - Shafer, Richard H.
PY - 1991/6/20
Y1 - 1991/6/20
N2 - The binding of spermine to the d(m5CGm5CGm5CG) duplex has been studied by proton and phosphorus nuclear magnetic resonance techniques in order to investigate the mobility and nature of spermine bound to the resulting Z-DNA complex. A characterization of the B to Z transition as a function of increasing spermine concentration demonstrated doubling of the non-exchangeable proton and the phosphorus peaks at a ratio of about 1:1 (spermine/duplex) and a re-simplification of the spectrum at 2:1 (spermine/duplex) where about 90% or the DNA was fully converted into the Z-form. However, some of the Z-DNA proton chemical shifts differed between the 1:1 and 2:1 titration points. Since these differences involved primarily the exchangeable terminal imino and amino protons, they could result from end effects. Discrepancies were generally not observed with the non-terminal proton shifts nor with the phosphorus shifts. These proton and phosphorus chemical shift changes are fully consistent with a, B to Z transition. Complexed spermine peaks appear about 0.1 parts per million upfield from the uncomplexed form. The spermine and both the B and Z-DNA hexamer signals are noticeably broadened at the 1:1 ratio but the remaining signals re-sharpen at the 2:1 ratio. Both one-dimensional and two-dimensional studies revealed negative nuclear Overhauser effect (NOE) contacts between each spermine proton. Therefore, spermine has a longer correlation time than that observed for unbounded spermine. These results are contrasted with the positive NOE contacts observed for the B-DNA-spermine complexes reported by Wemmer et al. using the dodecamer d(CGCGAATTCGCG)2 and reported here using the hexamer d(ATGCAT)2. While the mobility of spermine in the Z-DNA complex is significantly less than that of the B-DNA complex, no clear evidence of intermolecular spermine-DNA proton NOE contacts is observed.
AB - The binding of spermine to the d(m5CGm5CGm5CG) duplex has been studied by proton and phosphorus nuclear magnetic resonance techniques in order to investigate the mobility and nature of spermine bound to the resulting Z-DNA complex. A characterization of the B to Z transition as a function of increasing spermine concentration demonstrated doubling of the non-exchangeable proton and the phosphorus peaks at a ratio of about 1:1 (spermine/duplex) and a re-simplification of the spectrum at 2:1 (spermine/duplex) where about 90% or the DNA was fully converted into the Z-form. However, some of the Z-DNA proton chemical shifts differed between the 1:1 and 2:1 titration points. Since these differences involved primarily the exchangeable terminal imino and amino protons, they could result from end effects. Discrepancies were generally not observed with the non-terminal proton shifts nor with the phosphorus shifts. These proton and phosphorus chemical shift changes are fully consistent with a, B to Z transition. Complexed spermine peaks appear about 0.1 parts per million upfield from the uncomplexed form. The spermine and both the B and Z-DNA hexamer signals are noticeably broadened at the 1:1 ratio but the remaining signals re-sharpen at the 2:1 ratio. Both one-dimensional and two-dimensional studies revealed negative nuclear Overhauser effect (NOE) contacts between each spermine proton. Therefore, spermine has a longer correlation time than that observed for unbounded spermine. These results are contrasted with the positive NOE contacts observed for the B-DNA-spermine complexes reported by Wemmer et al. using the dodecamer d(CGCGAATTCGCG)2 and reported here using the hexamer d(ATGCAT)2. While the mobility of spermine in the Z-DNA complex is significantly less than that of the B-DNA complex, no clear evidence of intermolecular spermine-DNA proton NOE contacts is observed.
KW - B-DNA
KW - negative NOE contacts
KW - proton n.m.r.
KW - spermine mobility
KW - Z-DNA
UR - http://www.scopus.com/inward/record.url?scp=0025923233&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0025923233&partnerID=8YFLogxK
U2 - 10.1016/0022-2836(91)90652-M
DO - 10.1016/0022-2836(91)90652-M
M3 - Article
C2 - 1647463
AN - SCOPUS:0025923233
VL - 219
SP - 585
EP - 590
JO - Journal of Molecular Biology
JF - Journal of Molecular Biology
SN - 0022-2836
IS - 4
ER -