of 9
Supporting Information for
A Monofunctional Platinum Complex Coordinated to a
Rhodium
Metalloinsertor Selectively Binds Mismatched DNA in
the Minor
Groove
Alyson G. Weidmann and Jacqueline K. Barton*
Division of Chemistry and Chemical Engineering, Cal
ifornia Institute of Technology, Pasadena,
CA 91125, United States
S2
Scheme S1.
Synthesis of [Rh(chrysi)(phen)(DPE-Pt(NH
3
)
2
Cl]
3+
S3
Figure S1.
ESI-MS spectrum of [Rh(chrysi)(phen)(DPE-Pt(NH
3
)
2
Cl]
3+
;
m/z
= 1000.9 –
1006.9 (indicative of the Rh and Pt isotope pattern
s), calc 1003.251.
S4
Figure S2.
Representative sigmoidal curve (Boltzmann fit) of
photocleavage competition
titrations of [Rh(chrysi)(phen)(DPE-Pt(NH
3
)
2
Cl)]
3+
for binding constant determination at the CC
mismatch. K
B
was calculated by solving simultaneous equilibria
at the inflection point of the
curve. Experiments were conducted in buffer (50 mM
NaCl, 10 mM NaP
i
, pH 7.1) using 1 μM
hairpin DNA and 1 μM rac-[Rh(bpy)
2
chrysi]
3+,
with 0-15 μM [Rh(chrysi)(phen)(DPE-
Pt(NH
3
)
2
Cl)]
3+
competitor complex. Experiments were carried under
conditions minimizing Pt
coordination.
S5
Figure S3.
Quantification of platination of mismatched (CC, b
lue) and well-matched (CG,
red) duplex DNA (1 μM ) by [Rh(chrysi)(phen)(DPE-Pt
(NH
3
)
2
Cl)]
3+
(0.1 – 5 μM). Samples were
incubated at 37 °C for 2h and electrophoresed on a
20% denaturing PAGE gel. The amount of
platinated DNA (% Pt-DNA) is expressed as a fractio
n of the total DNA in each sample.
S6
Figure S4.
Quantification of DNA footprinting by methyl metha
nesulfonate (MMS) at purine
residues (
N
3-adenine and
N
7-guanine) in mismatched (left) and well-matched (r
ight)
radiolabeled DNA of the sequence indicated. The sit
e of the CC mismatch is denoted by the red
‘X.’ The location of each site of cleavage (A1, A2,
A3, A4 =
N
3-adenine methylation, denoted in
the sequence in blue; G1 =
N
7-guanine methylation, denoted in green) is indicat
ed in the
sequence. Not all purines in the labeled strand wer
e susceptible to MMS-induced depurination.
Duplex DNA was platinated with cisplatin (1 μM, red
bars), the metalloinsertor conjugate (1 or 5
μM; green and purple bars, respectively), or left u
ntreated (blue bars), alkylated with MMS, and
depurinated at methylated sites. The cleaved DNA wa
s electrophoresed on a 20% denaturing
PAGE gel, and the fraction of cleaved DNA at each s
ite is expressed as a fraction of the total
DNA in each sample.
S7
MALDI-TOF Mass Spectrometry of Platinated DNA Fragm
ents
S8
S9