Investigation of the nature of enzyme-coenzyme interactions in binary and ternary complexes of liver alcohol dehydrogenase with coenzymes, coenzyme analogs, and substrate analogs by ultraviolet absorption and phosphorescence spectroscopy

Subramanian, S.; Jb, Ross; Ross, PD; Brand, Ludwig

doi:10.1021/bi00517a022

Cited by 28 publications

(21 citation statements)

References 27 publications

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“…Furthermore, combining the enthalpy with entropy changes, interactions between HCPT and Ce6 molecules were mainly hydrophobic interaction (Δ H 1 >0, Δ S 1 >0; Δ H 3 >0, Δ S 3 >0) and electrostatic attraction (Δ H 2 <0, Δ S 2 >0). So it was confirmed that the assembly mechanism of the NRs was mainly the hydrophobic interaction (the π–π conjugation of the ring structure) and the electrostatic interaction between HCPT and Ce6 molecules 35,36. The association constant (n=3) indicated that one molecule of Ce6 probably combined with three HCPT molecules.…”

Section: Resultsmentioning

confidence: 78%

<p>Carrier-Free, Dual-Functional Nanorods Via Self-Assembly Of Pure Drug Molecules For Synergistic Chemo-Photodynamic Therapy</p>

Zhao¹,

Zhao²,

Ma³

et al. 2019

IJN

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BackgroundThe combination of chemo-photodynamic therapy based on nano-technology has emerged as a preferable and promising measure for synergetic antitumor therapy.PurposeThe aim of this study was expected to overcome most of the safety concerns from nano-carriers and improve the chemo-photodynamic synergistic antitumor efficacy.MethodsHerein, we reported a facile and effective approach based on the self-assembly of chemotherapeutic agent 10-hydroxycamptothecin (HCPT) and photosensitizer chlorin e6 (Ce6) for preparing stably dual-functional nanorods (NRs).ResultsThe chemical thermodynamic parameters obtained from isothermal titration calorimeter (ITC) and the microcosmic configuration snapshots acquired by molecular dynamics (MD) simulations verified that HCPT and Ce6 molecules tended to assemble with each other through various intermolecular forces. The as-prepared HCPT/Ce6 NRs possessed a relatively uniform size of around 165 nm and zeta potential of about −29 mV, together with good stability in aqueous solution and freeze-dried state. In addition, both the extra- and intracellular reactive oxygen species (ROS) generation capacity of the NRs under laser irradiation was significantly enhanced compared with Ce6 injections. Moreover, the dual-functional HCPT/Ce6 NRs exhibited a substantial in vitro/in vivo synergistic antitumor efficacy under laser irradiation due to the integration of the two therapeutic modalities into one drug delivery system. Besides, no obvious hepatic or renal toxicity was observed in the NRs treatment groups.ConclusionTaken together, HCPT/Ce6 NRs demonstrated a powerful efficacy in chemo-photodynamic therapy for breast cancer. Therefore, the carrier-free dual-functional NRs prepared in a facile and effective strategy might give inspiration for the development of combined antitumor therapy.

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Section: Resultsmentioning

confidence: 78%

<p>Carrier-Free, Dual-Functional Nanorods Via Self-Assembly Of Pure Drug Molecules For Synergistic Chemo-Photodynamic Therapy</p>

Zhao¹,

Zhao²,

Ma³

et al. 2019

IJN

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“…The mechanism for the quenching of the tryptophan fluorescence of ADH that results from formation of binary and ternary complexes has been the subject of controversy (Laws and Shore, 1978;Laws and Shore. 1979;Subramanian et al, 1981;Eftink, 1986). In the case of the pyrazole ternary complex with NAD + , singlet-singlet resonance energy transfer has been proposed as the mechanism for the preferential quenching of Trp-314 .…”

Section: Discussionmentioning

confidence: 99%

“…Triplet state investigations of pyridine nucleotide dependent enzymes have been limited to the aromatic amino acids. tyrosine and tryptophan (Purkey and Galley, 1970;von Schiitz et al, 1974;Subramanian et al, 1981). The pyridine nucleotide coenzymes are themselves potentially useful triplet state probes, and it is of interest that their triplet state characteristics complement their singlet state properties.…”

Section: Introductionmentioning

confidence: 99%

“…According to the X-ray crystal structure (Eklund and Branden, 1979), Trp-314 is in a hydrophobic environment at the dimer interface, and Trp-15 is in an aqueous environment exposed at the surface. Subramanian et al (1981) have investigated the tryptophan phosphorescence of ADH ternary complexes of the oxidized coenzyme with the inhibitors, trifluorethanol and pyrazole, as well as the ternary complex of the reduced coenzyme with the inhibitor, isobutyramide. They observed that in every case the tryptophan and tyrosine phosphorescence was quenched relative to the phosphorescence of the free enzyme.…”

Section: Introductionmentioning

confidence: 99%

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Phosphorescence Maxima and Triplet State Lifetimes of Nad + and Ε‐nad+ in Ternary Complexes With Horse Liver Alcohol Dehydrogenase

Rousslang

Allen

Ross

1989

Photochem & Photobiology

Self Cite

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This paper describes the phosphorescence emission and decay times of NAD+ and its fluorescent etheno derivative, epsilon-NAD+, in the pyrazole ternary complex with horse liver alcohol dehydrogenase (ADH). We show that the epsilon-NAD+ triplet state, as well as the tryptophan triplet state, can be utilized to monitor the coenzyme-enzyme interaction. The decays of NAD+ and AMP are single exponential, and the lifetimes are the same within experimental error. The phosphorescence lifetimes, evaluated as single exponentials, are slightly shorter in epsilon-NAD+ than they are in epsilon-AMP. Whereas the decay of epsilon-AMP was adequately fit by a single exponential with a time constant of very close to 0.5 s, it was necessary to fit the decay of epsilon-NAD+ to a double exponential. Ternary complexes with NAD+ excited at 297 nm exhibit decay kinetics nearly identical to those of ADH by itself. On the other hand, when excitation of the epsilon-NAD+ ternary complex is provided at 313 nm, where there is very little absorption by either tryptophan residue, the decay law of the ternary complex is similar to that of epsilon-NAD+ in solution. Our results demonstrate that NAD+ and epsilon-NAD+ quench tryptophan phosphorescence in ADH. Normalizing the phosphorescence intensity to the 0-0 vibronic band assigned to Trp-15 (blue-edge), we calculate a 21% decrease in the phosphorescence associated with Trp-314 at stoichiometric saturation of the coenzyme binding sites with NAD+ in the ternary complex. When the active sites are saturated with epsilon-NAD+, the relative phosphorescence due to Trp-314 decreases by 63%.(ABSTRACT TRUNCATED AT 250 WORDS)

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“…This can also be done in the presence of tryp-tophan because the phosphorescence spectra of tyrosinate and tryptophan are well resolved. (202) By contrast, phosphorescence or fluorescence resulting from excited-state ionization will have an excitation spectrum characteristic of tyrosine. Moreover, the decay kinetics of the product formed in the excited state will have a characteristic signature, specifically a kinetic component with a negative amplitude, (26) and short lifetime in the case of tyrosinate.…”

Section: Fluorescence Of Tyrosinatementioning

confidence: 99%

Tyrosine Fluorescence and Phosphorescence from Proteins and Polypeptides

Ross

Laws

Rousslang

et al.

Topics in Fluorescence Spectroscopy

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The fluorescence and phosphorescence of proteins and polypeptides is the sum of the contributions from the three aromatic amino acids tryptophan, tyrosine, and phenylalanine. The work on protein and polypeptide luminescence prior to 1971 has been reviewed in detail by Longworth. (1) Another fine account of the early work, emphasizing tryptophan and tyrosine, is the monograph by Konev. (2) An excellent review on tyrosine fluorescence in proteins and model peptides, for the period up to 1975, is given by Cowgill. (3) In 1984, Creed (4) reviewed the photophysics and photochemistry of tyrosine and its simple derivatives, including a thorough coverage of steady-state fluorescence and a brief discussion of triplet-state properties, but did not include any work on proteins or polypeptides.The first quantitative studies of the excited-state properties of the three aromatic amino acids were carried out in the 1950s. The low-temperature phosphorescence of the aromatic amino acids was initially observed by Debye and Edwards (5) in 1952, and phosphorescence emission spectra were reported by Steele and Szent-Gyorgyi (6) in 1957. In 1953, Weber (7) postulated that the fluorescence of the aromatic amino acids should occur in the near-ultraviolet region of the electromagnetic spectrum. In 1956, independently and almost simultaneously, Duggan and Udenfriend (8) and Shore and Pardee (9) reported the results of their investigations of protein fluorescence. At the same time,

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Investigation of the nature of enzyme-coenzyme interactions in binary and ternary complexes of liver alcohol dehydrogenase with coenzymes, coenzyme analogs, and substrate analogs by ultraviolet absorption and phosphorescence spectroscopy

Cited by 28 publications

References 27 publications

<p>Carrier-Free, Dual-Functional Nanorods Via Self-Assembly Of Pure Drug Molecules For Synergistic Chemo-Photodynamic Therapy</p>

<p>Carrier-Free, Dual-Functional Nanorods Via Self-Assembly Of Pure Drug Molecules For Synergistic Chemo-Photodynamic Therapy</p>

Phosphorescence Maxima and Triplet State Lifetimes of Nad + and Ε‐nad+ in Ternary Complexes With Horse Liver Alcohol Dehydrogenase

Tyrosine Fluorescence and Phosphorescence from Proteins and Polypeptides

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