Effects of single amino acid substitution on the dissociation of multiply charged multiprotein complexes in the gas phase

The effects of amino acid substitutions on the product ion charge distributions for protonated and deprotonated homogeneous and heterogeneous multiprotein complexes in the gas phase are studied using Fourier-transform mass spectrometry and the blackbody infrared radiative dissociation technique. Notably, it is shown that a single amino acid substitution in the leaving subunit can cause a small but measurable change in product ion charge distribution. Evidence that the degree of charge enrichment of the leaving subunit is influenced by the number of strongly basic or acidic residues within the subunit for the protonated and deprotonated complexes, respectively, is reported.     

On the maximum charge state and proton transfer reactivity of peptide and protein ions formed by electrospray ionization

A relatively simple model for calculation of the energetics of gas-phase proton transfer reactions and the maximum charge state of multiply protonated ions formed by electrospray ionization is presented. This model is based on estimates of the intrinsic proton transfer reactivity of sites of protonation and point charge Coulomb interactions. From this model, apparent gas-phase basicities (GB^app) of multiply protonated ions are calculated. Comparison of this value to the gas-phase basicity of the solvent from which an ion is formed enables a maximum charge state to be calculated. For 13 commonly electrosprayed proteins, our calculated maximum charge states are within an average of 6% of the experimental values reported in the literature. This indicates that the maximum charge state for proteins is determined by their gas-phase reactivity. Similar results are observed for peptides with many basic residues. For peptides with few basic residues, we find that the maximum charge state is better correlated to the charge state in solution. For low charge state ions, we find that the most basic sites Arg, Lys, and His are preferentially protonated. A significant fraction of the less basic residues Pro, Trp, and Gln are protonated in high charge state ions. The calculated GB^app of individual protonation sites varies dramatically in the high charge state ions. From these values, we calculate a reduced cross section for proton transfer reactivity that is significantly lower than the Langevin collision frequency when the GB^app of the ion is approximately equal to the GB of the neutral base.     

Spectral characteristics of 2-(4'-N,N-dimethylaminophenyl)pyrido[3,4-d]imidazole in AOT/n-heptane/water reverse micelles.

Spectral characteristics of 2-(4'-N,N-dimethylaminophenyl)pyrido[3,4-d]imidazole (DMAPPI) have been studied in AOT/n-heptane/water reverse micelles at w0 > or = 0. Absorption, fluorescence excitation and fluorescence spectra have revealed that the monocation (MC) of DMAPPI, protonated at the imidazole nitrogen (MC2) (Scheme 2) is present in the S0 state at w0 = 0, along with the MC, protonated at pyridine nitrogen (MC3) and only normal emission is observed from both MC2 and MC3. With increase in w0 (water amount), the equilibrium is shifted towards the MC, protonated at -NMe2 group (MC1) and MC3 in the S0 state. Biprotonic phototautomerism is observed in MC1 to generate MC2 in the S1 state. The twisted intramolecular charge transfer (TICT) emission replaces the normal emission in MC3. All the MCs are present near the anionic polar head group of AOT in the bound water region.     

A new approach for the study of gas-phase ion-ion reactions using electrospray ionization

A simple flow reactor which facilitates the study and application of ion-ion and ion-molecule reactions at near atmospheric pressures is reported. Reactant ions were generated by electrospray ionization and discharge ionization methods, although any ionization sources amenable to atmospheric pressure may be used. Ions of opposite charge are generated in spatially separate ion sources and are swept into capillary inlets where the flows are merged and where reaction(s) can occur. Among the reactions investigated were the partial neutralization of multiply protonated polypeptides and proteins such as melittin, bradykinin, cytochrome c, and myoglobin by reaction with discharge-generated anions, the partial neutralization of multiply charged anions of oligodeoxyadenylic acid (d(pA)₃) by reaction with discharge-generated cations, the partial neutralization of bovine A-chain insulin anions by reaction with myoglobin [M+nH]ⁿ⁺ ions, and the reaction of multiply protonated melittin with discharge-generated cations. The cation-anion reactions generally resulted in a shift to lower charge (higher mass-to-charge ratio) in the products’ charge state distributions and the transfer of solvent molecules to the macromolecule products. Multiply protonated melittin was detected in a less highly solvated state with the positive discharge in operation.     

Amplified potentiometric determination of pK(00), pK(0), pK(l), and pK(2) of hydrogen sulfides with Ag(2)S ISE

The chemical capacitor theory has been applied to accurately determine dissociation constants of H(2)S with the Ag(2)S ion-selective electrode (ISE). The theory's principle is based on the measurement of the change in electrode charge density as a result of protonated or unprotonated sulfide adsorbed on the electrode surface. This charge density is related to the potential. Connection of each individual capacitor in series amplifies the potential according to the equation, E(total)=E(1)+E(2)+E(3)+cdots, three dots, centeredE(n). As the charges of individual capacitors are concentrated to one capacitor area, the charge density rises, and the potential increases. The pK(00), pK(0), pK(1), and pK(2) are reported as 1.8, 2.12, 7.05, and 12.0, respectively. The pK(00) and pK(0) are reported here for the first time. The pK(1) agrees well with the literature values; however, the pK(2) differs from those reported recently under extreme conditions. Reasons for disproving the unreasonably high pK(2)>17-19 values are given based on calculations. Mainly, when pK(2)>17-19, the experimental results do not fit the equilibrium equations, pH=(pK(1)+pK(2))/2, pK(1)=(pK(0)+pK(2))/2, and pH=pK(2)+log(HS(-))/(S(2-)).     

Charge density flow as a driving force of distortion in excited protonated azaaromatics

The INDO method was used to calculate electronic charge densities in the ground and lowest excited singlet and triplet states of neutral and protonated 2,3- and 1,4-diaza derivatives of naphthalene and phenanthrene, and benzo (a) phenazine. Experiniental changes of pK_a upon excitation can be correlated with the values of electron density flow into the heterocy- clic ring. Electron-density increase turns out to be a major factor which causes distortion in some excited protonated species.     

Ion trap collision-induced dissociation of multiply deprotonated RNA: c/y-ions versus (a-B)/w-ions

The dissociation of model RNA anions has been studied as a function of anion charge state and excitation amplitude using ion trap collisional activation. Similar to DNA anions, the precursor ion charge state of an RNA anion plays an important role in directing the preferred dissociation channels. Generally, the complementary c/y-ions from 5′ P-O bond cleavage dominate at low to intermediate charge states, while other backbone cleavages appear to a limited extent but increase in number and relative abundance at higher excitation energies. The competition between base loss, either as a neutral or as an anion, as well as the preference for the identity of the lost base are also observed to be charge-state dependent. To gain further insight into the partitioning of the dissociation products among the various possible channels, model dinucleotide anions have been subjected to a systematic study. In comparison to DNA, the 2′-OH group on RNA significantly facilitates the dissociation of the 5′ P-O bond. However, the degree of excitation required for a 5′ base loss and the subsequent 3′ C-O bond cleavage are similar for the analogous RNA and DNA dinucleotides. Data collected for protonated dinucleotides, however, suggest that the 2′-OH group in RNA can stabilize the glycosidic bond of a protonated base. Therefore, base loss from low charge state oligonucleotide anions, in which protonation of one or more bases via intramolecular proton transfer can occur, may also be stabilized in RNA anions relative to corresponding DNA anions.     

Effect of charge distribution on electrostatic chromophore—protein interactions in Bacteriorhodopsin

Charge distributions of a protonated and unprotonated Schiff base model compound are determined using different quantum chemical methods. After fitting the model molecule onto the protonated retinal Schiff base in Bacteriorhodopsin, electrostatic interaction energies between the model molecule and protein are calculated. Interaction energies as well as the calculated pK_1/2 values of the model molecule are shown to depend considerably on the chosen charge distribution. Electrostatic potential derived partial charges determined at different ab initio levels reveal interaction energies between the model molecule and nearby residues such as ARG-82, ASP-85, and ASP-212, which are relatively method independent. Consequently, such charge distributions also result in pK_1/2 values for the model molecule that are very similar. Larger deviations in the electrostatic interaction energies, however, are found in the case of charge distributions derived according to the Mulliken population analysis. Nevertheless, some sets of Mulliken derived partial charges predicted pK_1/2 values for the model molecule that are close to those determined with electrostatic potential derived partial charges. This agreement, however, is only achieved because the individual errors of the contributing terms are approximately compensated. The use of the extended atom model is shown to be problematic. Although potential derived charges can correctly describe electrostatic interaction energies, they fail to predict pK_1/2 values. On the basis of the present investigation a new set of partial charges for the protonated and unprotonated retinal Schiff base is proposed to be used in molecular dynamics simulations and electrostatics calculations. © 1997 by John Wiley & Sons, Inc.     

Blackbody infrared radiative dissociation of bradykinin and its analogues: energetics, dynamics, and evidence for salt-bridge structures in the gas phase

Blackbody infrared radiative dissociation (BIRD) spectra of singly and doubly protonated bradykinin and its analogues are measured in a Fourier-transform mass spectrometer. Rate constants for dissociation are measured as a function of temperature with reaction delays up to 600 s. From these data, Arrhenius activation parameters in the zero-pressure limit are obtained. The activation parameters and dissociation products for the singly protonated ions are highly sensitive to small changes in ion structure. The Arrhenius activation energy (E(a)) and pre-exponential (or frequency factor, A) of the singly protonated ions investigated here range from 0.6 to 1.4 eV and 10(5) to 10(12) s(-1), respectively. For bradykinin and its analogues differing by modification of the residues between the two arginine groups on either end of the molecule, the singly and doubly protonated ions have average activation energies of 1.2 and 0.8 eV, respectively, and average A values of 10(8) and 10(12) s(-1), respectively, i.e., the presence of a second charge reduces the activation energy by 0.4 eV and decreases the A value by a factor of 10(4). This demonstrates that the presence of a second charge can dramatically influence the dissociation dynamics of these ions. The doubly protonated methyl ester of bradykinin has an E(a) of 0.82 eV, comparable to the value of 0.84 eV for bradykinin itself. However, this value is 0.21 +/- 0.08 eV greater than that of singly protonated methyl ester of bradykinin, indicating that the Coulomb repulsion is not the most significant factor in the activation energy of this ion. Both singly and doubly protonated Lys-bradykinin ions have higher activation energies than the corresponding bradykinin ions indicating that the addition of a basic residue stabilizes these ions with respect to dissociation. Methylation of the carboxylic acid group of the C-terminus reduces the E(a) of bradykinin from 1.3 to 0.6 eV and the A factor from 1012 to 105 s(-1). This modification also dramatically changes the dissociation products. Similar results are observed for [Ala(6)]-bradykinin and its methyl ester. These results, in combination with others presented here, provide experimental evidence that the most stable form of singly protonated bradykinin is a salt-bridge structure.     

Reaction of C2H2(+) (n · ν2, m · ν5) with NO2: reaction on the singlet and triplet surfaces

Integral cross sections and product recoil velocity distributions were measured for reaction of C(2)H(2)(+) with NO(2), in which the C(2)H(2)(+) reactant was prepared in its ground state, and with mode-selective excitation in the cis-bend (2ν(5)) and CC stretch (n · ν(2), n = 1, 2). Because both reactants have one unpaired electron, collisions can occur with either singlet or triplet coupling of these unpaired electrons, and the contributions are separated based on distinct recoil dynamics. For singlet coupling, reaction efficiency is near unity, with significant branching to charge transfer (NO(2)(+)), O(-) transfer (NO(+)), and O transfer (C(2)H(2)O(+)) products. For triplet coupling, reaction efficiency varies between 13% and 19%, depending on collision energy. The only significant triplet channel is NO(+) + triplet ketene, generated predominantly by O(-) transfer, with a possible contribution from dissociative charge transfer at high collision energies. NO(2)(+) formation (charge transfer) can only occur on the singlet surface, and appears to be mediated by a weakly bound complex at low energies. O transfer (C(2)H(2)O(+)) also appears to be dominated by reaction on the singlet surface, but is quite inefficient, suggesting a bottleneck limiting coupling to this product from the singlet reaction coordinate. The dominant channel is O(-) transfer, producing NO(+), with roughly equal contributions from reaction on singlet and triplet surfaces. The effects of C(2)H(2)(+) vibration are modest, but mode specific. For all three product channels (i.e., charge, O(-), and O transfer), excitation of the CC stretch fundamental (ν(2)) has little effect, 2 · ν(2) excitation results in ～50% reduction in reactivity, and excitation of the cis-bend overtone (2 · ν(5)) results in ～50% enhancement. The fact that all channels have similar mode dependence suggests that the rate-limiting step, where vibrational excitation has its effect, is early on the reaction coordinate, and branching to the individual product channels occurs later.     

Investigation of the pronounced medium effects observed in the voltammetry of the highly charged lacunary anions [alpha-SiW11O39]8- and [alpha-PW11O39]7-

A detailed study is reported of the influence of protons, metal cations, and media on the redox chemistry of lacunary anions [alpha-SiW11O39]8- and [alpha-PW11O39]7- of high formal negative charge. Each anion displayed a single chemically reversible one-electron reduction process in carefully dried aprotic CH3CN solution. This process was detected at very negative potentials just prior to the solvent limit. Addition of 0.3 equiv of acid gave rise to a new reduction process at considerably less negative potentials, which is attributed to formation of the protonated species [SiW11O38(OH)]7- and [PW11O38(OH)]6-. Voltammograms derived from simulations based on a double-square scheme are in excellent agreement with experiment. Previous data reported the presence of several processes in CH3CN and appear to have been influenced by the presence of protons and/or adventitious water. Not surprisingly, protonation reactions coupled to charge transfer contribute significantly to the voltammetry of these lacunary anions in buffered aqueous media over the pH range 2-6. A multi-square-scheme mechanism allowed the essential thermodynamic and kinetic features of this system to be captured and an assessment of the relative significance of possible individual pathways. The high formal anionic charges of [SiW11O39]8- and [PW11O39]7- appear to provide highly basic reduced forms that are able to abstract protons from water to produce protonated species which are reduced at potentials more than a volt less negative than those for the processes [SiW11O39]8-/9- and [PW11O39]7-/8- found in dry aprotic media.     

Disparity between solution-phase equilibria and charge state distributions in positive-ion electrospray mass spectrometry

Two peptides, bradykinin and gramicidin S, were used to investigate the relationship between protonation in the solution phase and charge state distribution observed in electrospray ionization (ES) mass spectra. The degree of protonation in solution was estimated using acid-base equilibrium calculations where possible. Protonation in solution was varied by adjusting pH, solvent composition and peptide concentration. Major disparities were observed between calculated solution-phase peptide protonation and the charge state distributions observed in ES mass spectra. The [(M + 2H)²⁺]/[(M + H)⁺] ratio calculated in solution was larger than the abundance ratio (M + 2H)²⁺ /(M + H)⁺ in the ES mass spectra of all acidic aqueous (pH < 6.5) and non-aqueous solutions; in basic aqueous solutions (pH > 9.5) the opposite was true. At high pH, electrophoretic droplet charging may reduce the activity of OH^? in positively charged droplets. The results at low pH imply the existence of supplementary factors in the ES ionization process which largely attenuate the degree of charging in the gas phase as compared with solution. Factors such as the increasing intra- and intermolecular coulombic repulsion between charge carriers (protons) and increasing attractive forces between protonated sites and counterions at progressively later stages of charged droplet evaporation were hypothesized to be chiefly responsible for this effect. Non-aqueous solvents of high basicity compete with analytes to some extent for available protons, forming protonated solvent molecules while decreasing the sensitivity and the degree of multiple charging of peptides.     

Green amorphous nanoplex as a new supersaturating drug delivery system

The nanoscale formulation of amorphous drugs represents a highly viable supersaturating drug-delivery system for enhancing the bioavailability of poorly soluble drugs. Herein we present a new formulation of a nanoscale amorphous drug in the form of a drug-polyelectrolyte nanoparticle complex (or nanoplex), where the nanoplex is held together by the combination of a drug-polyelectrolyte electrostatic interaction and an interdrug hydrophobic interaction. The nanoplex is prepared by a truly simple, green process that involves the ambient mixing of drug and polyelectrolyte (PE) solutions in the presence of salt. Nanoplexes of poorly soluble acidic (i.e., ibuprofen and curcumin) and basic (i.e., ciprofloxacin) drugs are successfully prepared using biocompatible poly(allylamine hydrochloride) and dextran sulfate as the PE, respectively. The roles of salt, drug, and PE in nanoplex formation are examined from ternary phase diagrams of the drug-PE complex, from which the importance of the drug's charge density and hydrophobicity, as well as the PE ionization at different pH values, is recognized. Under the optimal conditions, the three nanoplexes exhibit high drug loadings of ~80-85% owing to the high drug complexation efficiency (~90-96%), which is achieved by keeping the feed charge ratio of the drug to PE below unity (i.e., excess PE). The nanoplex sizes are ~300-500 nm depending on the drug hydrophobicity. The nanoplex powders remain amorphous after 1 month of storage, indicating the high stability owed to the PE's high glass-transition temperature. FT-IR analysis shows that functional groups of the drug are conserved upon complexation. The nanoplexes are capable of generating prolonged supersaturation upon dissolution with precipitation inhibitors. The supersaturation level depends on the saturation solubility of the native drugs, where the lower the saturation solubility, the higher the supersaturation level. The solubility of curcumin as the least-soluble drug is magnified 9-fold upon its transformation to the nanoplex, and the supersaturated condition is maintained for 5 h.     

Dynamical effects on vibrational and electronic spectra of hydroperoxyl radical water clusters

We have carried out ab initio molecular-dynamics studies on hydroperoxyl water clusters. Our studies are complemented by optimization, frequency, and excited-state calculations. The three main results we obtained are (a) the dynamically averaged energy gap between the highest-occupied molecular orbital and the lowest-unoccupied molecular orbital monotonically decreases as the number of water molecules is increased in a hydroperoxyl water cluster system, (b) the dynamical averaging of the potential-energy surface at finite temperature broadens the electronic excitation spectrum and changes the infrared spectrum in nontrivial ways, and (c) the structural analysis of our dynamics simulation indicates that the oxygen-oxygen distance in a solvated hydroperoxyl-water cluster is very similar to that found in protonated water clusters (Zundel: H5O2+) inspite of the fact that the latter possesses a positive charge and the hydroperoxyl-water cluster does not. Dynamical charge analysis and the weak acidity of HO2 are used to justify this result.     

Photodissociation spectroscopy and dynamics of the CH2CFO radical

The photodissociation spectroscopy and dynamics resulting from excitation of the B (2)A(")<--X (2)A(") transition of CH(2)CFO have been examined using fast beam photofragment translational spectroscopy. The photofragment yield spectrum reveals vibrationally resolved structure between 29 870 and 38 800 cm(-1), extending approximately 6000 cm(-1) higher in energy than previously reported in a laser-induced fluorescence excitation spectrum. At all photon energies investigated, only the CH(2)F+CO and HCCO+HF fragment channels are observed. Both product channels yield photofragment translational energy distributions that are characteristic of a decay mechanism with a barrier to dissociation. Using the barrier impulsive model, it is shown that fragmentation to CH(2)F+CO products occurs on the ground state potential energy surface with the isomerization barrier between CH(2)CFO and CH(2)FCO governing the observed translational energy distributions.     

Effects of Gas-Phase Basicity on the Proton Transfer between Organic Bases and Trifluoroacetic Acid in the Gas Phase: Energetics of Charge Solvation and Salt Bridges

The unimolecular dissociation pathways and kinetics of a series of protonated trimer ions consisting of two organic bases and trifluoroacetic acid were investigated using blackbody infrared radiative dissociation. Five bases with gas-phase basicities (GB) ranging from 238.4 to 246.2 kcal/mol were used. Both the dissociation pathways and the threshold dissociation energies depend on the GB of the base. Trimers consisting of the two most basic molecules dissociate to form protonated base monomers with an E(0) ~ 1.4 eV. Trimers consisting of the two least basic molecules dissociate to form protonated base dimers with an E(0) ~ 1.1-1.2 eV. These results indicate that the structures of the trimers change as a function of the GB of the basic molecule. The predominant structure of the protonated trimers consisting of the two most basic molecules is consistent with a salt bridge in which both of the basic molecules are protonated, and the trifluoroacetic acid molecule is deprotonated, whereas the predominant structure of the protonated trimers consisting of the two least basic molecules are consistent with charge-solvated complexes in which the proton is shared. The structure of the trimer consisting of the base of intermediate basicity is less clear; it dissociates to form primarily protonated base dimer, but has an E(0) ~ 1.2 eV. These results are consistent with the structure of this trimer as a salt bridge, but the resulting dissociation A(-). BH(+) product does not appear to be stable as an ion pair in the dissociative transition state.     

酸碱控制的卟啉-苝酰亚胺分子阵列荧光开关

研究了氯仿溶液中分子阵列N,N-二[对-5′-(间-10′,15′,20′-三苯基卟啉)基-苯基]-3,4:9,10-四羧基二酰亚胺(TrPP-PTCDI-TrPP)在不同浓度的三氟乙酸作用下荧光光谱的变化,质子化无金属卟啉的光致激发态成为各种激发态中相对稳定的物种,因此无论激发无金属卟啉基元(λ=439nm)还是酰亚胺基元(λ=491nm),分子阵列都表现出质子化无金属卟啉生色团的特征荧光发射,酸的引入使激发态下高效率的电荷转移衰变途径被关闭,辐射衰变途径被打开.在溶液中引入三乙胺去质子化使电荷转移衰变途径被打开而辐射衰变途径被关闭,因此分子阵列构成了一个通过酸碱控制的荧光开关.考虑到酸碱中和反应的方便性及分子阵列对不同波段光激发同时敏感的广谱性,该分子阵列开关具有特殊优势.     

Comparison of the fragmentation pattern induced by collisions, laser excitation and electron capture. Influence of the initial excitation

Collision-induced dissociation, laser-induced dissociation and electron-capture dissociation are compared on a singly and doubly protonated pentapeptide. The dissociation spectrum depends on the excitation mechanism and on the charge state of the peptide. The comparison of these results with the conformations obtained from Monte Carlo simulations suggests that the de-excitation mechanism following a laser or an electron-capture excitation is related to the initial geometry of the peptide.     

Sequential hydration of small protonated peptides

The sequential addition of water molecules to a series of small protonated peptides was studied by equilibrium experiments using electrospray ionization combined with drift cell techniques. The experimental data were compared to theoretical structures of selected hydrated species obtained by molecular mechanics simulations. The sequential water binding energies were measured to be of the order of 7-15 kcal/mol, with the largest values for the first water molecule adding to either a small nonarginine containing peptide (e.g., protonated dialanine) or to a larger peptide in a high charge state (e.g., triply protonated neurotensin). General trends are (a) that the first water molecules are more strongly bound than the following water molecules, (b) that very small peptides (2-3 residues) bind the first few water molecules more strongly than larger peptides, (c) that the first few water molecules bind more strongly to higher charge states than to lower charge states, and (d) that water binds less strongly to a protonated guanidino group (arginine containing peptides) than to a protonated amino group. Experimental differential entropies of hydration were found to be of the order of -20 cal/mol/K although values vary from system to system. At constant experimental conditions the number of water molecules adding to any peptide ion is strongly dependent on the peptide charge state (with higher charge states adding proportionally more water molecules) and only weakly dependent on the choice of peptide. For small peptides molecular mechanics calculations indicate that the first few water molecules add preferentially to the site of protonation until a complete solvation shell is formed around the charge. Subsequent water molecules add either to water molecules of the first solvation shell or add to charge remote functional groups of the peptide. In larger peptides, charge remote sites generally compete more effectively with charge proximate sites even for the first few water molecules.     

Ultrafast excitation transfer and charge stabilization in a newly assembled photosynthetic antenna-reaction center mimic composed of boron dipyrrin, zinc porphyrin and fullerene

A self-assembled supramolecular triad as a model to mimic the light-induced events of the photosynthetic antenna-reaction center, that is, ultrafast excitation transfer followed by electron transfer ultimately generating a long-lived charge-separated state, has been accomplished. Boron dipyrrin (BDP), zinc porphyrin (ZnP) and fullerene (C(60)), respectively, constitute the energy donor, electron donor and electron acceptor segments of the antenna-reaction center imitation. Unlike in the previous models, the BDP entity was placed between the electron donor, ZnP and electron acceptor, C(60) entities. For the construction, benzo-18-crown-6 functionalized BDP was synthesized and subsequently reacted with 3,4-dihydroxyphenyl functionalized ZnP through the central boron atom to form the crown-BDP-ZnP dyad. Next, an alkyl ammonium functionalized fullerene was used to self-assemble the crown ether entity of the dyad via ion-dipole interactions. The newly formed supramolecular triad was fully characterized by spectroscopic, computational and electrochemical methods. Steady-state fluorescence and excitation studies revealed the occurrence of energy transfer upon selective excitation of the BDP in the dyad. Further studies involving the pump-probe technique revealed excitation transfer from the (1)BDP* to ZnP to occur in about 7 ps, much faster than that reported for other systems in this series of triads, as a consequence of shorter distance between the entities. Upon forming the supramolecular triad by self-assembling fullerene, the (1)ZnP(*) produced by direct excitation or by energy transfer mechanism resulted in an initial electron transfer to the BDP entity. The charge recombination resulted in the population of the triplet excited state of C(60), from where additional electron transfer occurred to produce C(60)(?-):crown-BDP-ZnP(?+) ion pair as the final charge-separated species. Nanosecond transient absorption studies revealed the lifetime of the charge-separated state to be ~100 μs, the longest ever reported for this type of antenna-reaction center mimics, indicating better charge stabilization as a result of the different disposition of the entities of the supramolecular triad.