External electric field effects both on monomer fluorescence emitted from the locally excited state and on exciplex fluorescence emitted following photoinduced electron transfer have been examined for some methylene linked compounds composed of electron donor and acceptor in a PMMA polymer film. Based on the results, external electric field effects on initial step of the electron transfer, charge recombination and charge migration are discussed. The field effects markedly depend on the methylene chain length and depend on the pair of electron donor and acceptorIntroduction.

Annals of the New York Academy of SciencesVolume 878, Issue 1 p. 622-624 Development and Application of a Microplate Assay Method for the Mass Screening of MMP Inhibitors TOSHIFUMI AKIZAWA, Corresponding Author TOSHIFUMI AKIZAWA Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101, Corresponding author. Phone/fax, +81-720-66-3129; e-mail, akizawa@pharm.setsunan.ac.jpSearch for more papers by this authorTAKAYUKI URATANI, TAKAYUKI URATANI Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorMOTOMI MATSUKAWA, MOTOMI MATSUKAWA Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorASUKA KUNIMATSU, ASUKA KUNIMATSU Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorYUKO ITO, YUKO ITO Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorMICHIYASU ITOH, MICHIYASU ITOH Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorYUKIO OHSHIBA, YUKIO OHSHIBA Meiji Milk Products Co., Ltd., 26-11, Midori 1-chome, Sumida-ku, Tokyo 130-8502, JapanSearch for more papers by this authorMASASHI YAMADA, MASASHI YAMADA Meiji Milk Products Co., Ltd., 26-11, Midori 1-chome, Sumida-ku, Tokyo 130-8502, JapanSearch for more papers by this authorMOTOHARU SEIKI, MOTOHARU SEIKI Department of Cancer Cell Research, Institute of Medical Sciences, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, JapanSearch for more papers by this author TOSHIFUMI AKIZAWA, Corresponding Author TOSHIFUMI AKIZAWA Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101, Corresponding author. Phone/fax, +81-720-66-3129; e-mail, akizawa@pharm.setsunan.ac.jpSearch for more papers by this authorTAKAYUKI URATANI, TAKAYUKI URATANI Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorMOTOMI MATSUKAWA, MOTOMI MATSUKAWA Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorASUKA KUNIMATSU, ASUKA KUNIMATSU Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorYUKO ITO, YUKO ITO Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorMICHIYASU ITOH, MICHIYASU ITOH Department of Analytical Chemistry, Faculty of Pharmaceutical Sciences, Setsunan University, 45-1, Nagaotoge-cho, Hirakata, Osaka 573-0101,Search for more papers by this authorYUKIO OHSHIBA, YUKIO OHSHIBA Meiji Milk Products Co., Ltd., 26-11, Midori 1-chome, Sumida-ku, Tokyo 130-8502, JapanSearch for more papers by this authorMASASHI YAMADA, MASASHI YAMADA Meiji Milk Products Co., Ltd., 26-11, Midori 1-chome, Sumida-ku, Tokyo 130-8502, JapanSearch for more papers by this authorMOTOHARU SEIKI, MOTOHARU SEIKI Department of Cancer Cell Research, Institute of Medical Sciences, University of Tokyo, 4-6-1, Shirokanedai, Minato-ku, Tokyo 108-8639, JapanSearch for more papers by this author First published: 06 February 2006 https://doi.org/10.1111/j.1749-6632.1999.tb07744.xCitations: 1Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL Share a linkShare onFacebookTwitterLinked InRedditWechat Citing Literature Volume878, Issue1INHIBITION OF MATRIX METALLOPROTEINASES THERAPEUTIC APPLICATIONSJune 1999Pages 622-624 RelatedInformation

The carbon-14 concentration in tree-ring cellulose of an 80-year-old pine tree which has been used for tritium measurement was measured during the 1941–1987 period. This was done to determine the formation year of each tree ring in order to study the pathway of tritium uptake into the tree rings. In the 1941 to 1953 period, the Δ14C value remained slightly lower than 0%., It began to increase from 1954 to a small broad peak of 250% between 1959 and 1961, followed by rapid increase to the highest value of approximately 800% in 1964. Since 1964, it had been diminishing year by year to reach a level of 190% in 1987. The two peak years coincided with those in the known carbon-14 patterns in tree rings. However, there existed a difference in the amplitude of the Δ14C values during the period of 1963–1967.

Fluorescence emitted from the pyrene chromophore is quenched by an electric field and both intra- and intermolecular electron transfer processes from N,N-dimethylaniline (DMA) to the excited state of pyrene are suggested as being enhanced by an electric field in a methylene-linked compound of pyrene and DMA doped in a PMMA polymer film. Exciplex fluorescence, which appears as a result of photoinduced electron transfer, shows field-induced enhancement and quenching, depending on the concentration. Quenching of the exciplex fluorescence observed at high concentrations is attributed to a photocarrier generation.

The excimer formation and photodissociation in jet-cooled molecular clusters of 1-cyanonaphthalene (1-CNN) and its deuterated compound (1-CNN-d(7)) were investigated. The jet-cooled excimer fluorescence was observed in the excitation cluster band (n greater than or equal to 4) of 1-CNN-d7 as well as of 1-CNN. The excitation of the excimer at 700-750 nm results in a considerably strong depletion of the excimer fluorescence and a simultaneous fragment fluorescence of the clusters at 335-350 nm. An excimer depletion spectrum was observed at 700-750 nm from the wavelength dependence of the depletion laser of the fragment intensity. Comparison of the excimer depletion spectrum of the jet-cooled cluster with that of the transient absorption of the excimer in solution suggests that the excitation into the upper state of the excimer induces the photodissociation of the excimer and the simultaneous fluorescence of the fragment. Fluorescence decay times of the fragment by the excimer depletion were considerably larger than those of the monomer and smaller than the dimer's. The photodissociation mechanism of the excimer was discussed in terms of decay times of the fragment fluorescence and the unexpectedly stable dimer core of 1-CNN.

The chain-end groups of the polypropylene (PP) polymerized without addition of molecular hydrogen over a MgCl2·TiCl4·dioctylphthalate/Et3Al catalyst system consisted of n-butyl, n-propyl, vinylidene and vinyl groups in addition to ethyl and i-butyl groups which were detected in the PP prepared under the same polymerization conditions except for the addition of diphenyldimethoxysilane (DPDMS) as an external donor. The newly detected chain-end groups indicate that the additional chain-transfer reactions were brought about by Et3Al at 2,1-inserted sites and by β-hydrogen elimination at both 1,2- and 2,1-inserted sites. These chain-transfer reactions could account for the observed drops of the activity and the molecular weight in the absence of DPDMS. In addition, the detected chain ends in the PP polymerized with addition of molecular hydrogen over this catalyst system having no DPDMS suggest that the molecular hydrogen addition leads not only to the conversion of the dormant 2,1-inserted sites into the active sites, but also to a decrease in the frequency of 2,1-insertion.

The intramolecular exciplex formation and photodissociation in a supersonic free jet have been studied for deuterated anthryl bichromophoric EDA systems 1-(9-anthryl-d(8))-3-(m-(N,N-dimethylamino)phenyl)propanes (9-An-d-m-DMA) in comparison with the corresponding undeuterated compounds (9-An-m-DMA). Fluorescence hole burning depletion spectra in the anthryl deuterated 9-An-d-m-DMA suggests the presence of two distinct isomeric conformers. The S-1 vibrational energy thresholds for the exciplex formation in the two isomeric forms of the deuterated compounds are considerably smaller than those of the respective undeuterated compounds. The photodissociation of the exciplex leading to the formation of the excited-state anthryl moiety was observed in the excitation of the transient absorption band of the jet-cooled exciplex (S-n-S-1). The decay time of the photodissociation-induced anthryl fluorescence is shorter for 9-An-d-m-DMA than for 9-An-d-m-DMA These deuteration effects of the anthryl moiety on the formation and photodissociation of the exciplex may be attributed to the role of the vibrational level density of the anthryl moiety in these excited-state reaction dynamics. The shorter decay time of the photodissociation-induced anthryl fluorescence of 9-An-d-m-DMA relative to 9-An-m-DMA is consistent with the conclusion that the emission originates from the vibrationally highly excited S-1 anthryl moiety.

Significantly Stokes-shifted fluorescence induced by the UV photoexcitation of 2,2'-bipyridin-3-ol in 3-methylpentane exhibits a dramatic temperature dependence such that dual fluorescence spectra (lambda(max) = 560 and 585 nm) at room temperature are replaced by a single fluorescence spectrum (lambda(max) = 560 nm) below 200 K. The respective emitting species responsible for the short- and long-wavelength bands may be ascribed to the excited-state primary phototautomer (S-1') and its rotamer (S-1 "), which is generated by, the rotational isomerization of S-1' with an activation barrier.

A simple and convenient method for measuring the activity of a recombinant human matrix metalloproteinase 7 (MMP-7, matrilysin) was developed by flow injection analysis (FIA). For this method, purified recombinant MMP-7 zymogen expressed in E. coli and the substrate peptide (MOCAc-Pro-Leu-Gly-Leu-A2pr(DNP)-Ala-Arg-NH2) were used. Following the incubation of substrate peptide with activated r-proMMP-7, the resulting fluorescent product peptide (MOCAc-Pro-Leu-Gly) was monitored with a fluorescence detector (λex 328 nm, λem 393 nm) without chromatographic separation. In this FIA system, the analysis time is 2 min and the standard curve is linear from 5 to 100 pmol of the product peptide injected. In order to use this FIA system as a method for screening inhibitors against MMP-7, the effects of CaCl2, EDTA and of the tissue inhibitor of metalloproteinase-1, and -2, were tested. A synthetic PRCGXPD-containing peptide (BS-10) was also observed to inhibit MMP-7 activity, with an IC50 value of 104 μM. Thus, it was concluded that the activity of r-MMP-7 can be reliably measured by the proposed system. Furthermore, to confirm the utility of this FIA system as a screening method, the inhibitory activity of the MMP-related substance in Joro spider (Nephila clavata) venom was measured by this method. This inhibitory activity was observed in an extract of a venom diluted 1000-fold. Thus, the FIA method is not only simple and quick, but also sensitive enough to screen and analyze the inhibitory properties of a large number of test compounds.

The jet-cooled intramolecular exciplex formation and photodissociation were examined in deuterated anthryl bichromophoric EDA systems 1-(9-anthryl-d(8))-3-(p-(N,N-dimethylamino (9-An-d-DMA) in comparison with the undeuterated compound (9-An-DMA) reported previously. The excess vibrational energy threshold for the exciplex formation in the former was considerably smaller than that of the latter. The photodissociation of the jet-cooled exciplex leading to the anthryl moiety fluorescence was observed in the excitation of the transient absorption band of the exciplex (S-n <-- S-1). It is noteworthy that very short decay times of anthryl fluorescence were observed upon photodissociation of the exciplex. The deuterated effect of the anthryl moiety on the formation and photodissociation of the exciplex may be attributable to the role of the vibrational level density of the anthryl in these excited-state reaction dynamics.

Time-resolved infrared absorption spectra of 7-hydroxyquinoline (7-HQ) in methanol were measured to investigate the relaxation processes following S-l --> S-l proton transfer tautumerization. Deuterium and nitrogen isotope effects were observed for the transient infrared spectra of 7-HQ-N-14 and -N-15 in MeOD and MeOH. The 1644 (1628) cm(-1) band in MeOH (MeOD) is ascribed to the H(D)-bonded C = O stretching of the phototautomer in the ground state (S-0'). Transient absorption decay exhibits a remarkable deuterium isotope effect, It is thus demonstrated that the ground-state reverse proton transfer of S-0', is responsible for the observed transient decay.

Excited-state charge transfer interaction was studied in bichromophoric electron donor-acceptor (EDA) systems, 1- and 9-(p-N,N-(dimethylamino)phenylethyloxy)anthracenes (1- and 9-An-O(CH2)(2)-DMA) and 1- and 9-(p-N,N-(dimethylamino)benzyloxy)methylanthracenes (1- and 9-An-CH2OCH2-DMA), in supersonic expansion. Intramolecular exciplex fluorescence, depending on excess vibrational energy, was observed in jet-cooled 9-An-O(CH2)(2)-DMA. In 1-An-O-(CH2)(2)-DMA, the existence of two isomeric conformers was observed in fluorescence excitation, spectra, The UV fluorescence excitation spectrum shows well-resolved vibrational structures, while the visible fluorescence excitation spectrum exhibits considerably broad and 4.5 nm blue-shifted vibrational structures from the UV excitation spectrum. The latter visible excitation spectrum is attributable to intramolecular van der Waals interaction between EDA moieties followed by the exciplex formation. Another conformer exhibits no significant exciplex fluorescence. The other ethereal compounds, 1- and 9-An-CH2OCH2-DMA, exhibit neither exciplex nor charge-transfer complex fluorescence in supersonic expansion but show exciplex fluorescence in solution.

Human matrix metalloproteinase-7 (MMP-7=matrilysin) was overproduced in Escherichia coli as a recombinant zymogen (31 kDa), the C-terminus of which bears artificial hexa-histidines. Most of the enzyme was isolated from the insoluble fraction of the cell lysate and purified by a single step using Ni-NTA resin after solubilization of the precipitates with 8 M urea solution. The resin-bound recombinant protein was refolded into a form that is activatable by p-amino-phenylmercuric acetate in an autocatalytic manner. The activated enzyme cleaved a synthetic peptide substrate at the reported site for MMP-7. Digestion of carboxymethylated transferrin (a natural substrate of MMP-7) by the recombinant proteinase generated fragments with the same peptide map as in the case of native purified MMP-7. The autocatalytic activation and enzyme reaction were entirely dependent on the presence of calcium and zinc ions, The enzyme activity to cleave carboxymethylated transferrin was inhibited by tissue inhibitors of metalloproteinases-1 and -2, MMP-specific inhibitors. The activity of the recombinant MMP-7 was also inhibited by a synthetic peptide derived from a part of the cysteine switch that maintains the zymogen in an inactive state. Thus, we report here a simple means of preparing a large quantity of recombinant proMMP-7 that can be used to study the activation mechanism and to screen synthetic inhibitors.

Triplet-triplet (T-1 --> T-0) fluorescence spectra and decay curves of diphenylcarbene (DPC) in the absence and in the presence of dye molecules such as Rhodamine 6G and Rhodamine B were measured in several organic glasses at 77 K. In the absence of dye molecules, the T-1 --> T-0 fluorescence signals exhibit biexponential decay with the lifetimes of similar to 30 and similar to 140 ns, which are attributable to the independent T-1 --> T-0 emission from the individual T-1 sublevels of DPC. In the presence of dye molecules, fluorescence decay signals of both fast and slow components were well analyzed in terms of resonance energy transfer of Forster type from DPC to dye molecule, The reaction scheme of the energy transfer and their various parameters are discussed on the basis of the independent T-1 --> T-0 emission from the individual T-1 sublevels of DPC at low temperature.

Selective excitation of benzil in the presence of 3-hydroxyflavone (3HF) in fluid solution results in diffusional triplet energy transfer from benzil to 3HF, and the Tn←T1 absorption spectrum of 3HF (acceptor) was determined by transient absorption spectroscopy. It is demonstrated that red probe pulse excitation of the lowest triplet state (T1) of the normal tautomer yields green fluorescence from the phototautomer in the lowest excited singlet state (S′1). Generation of S′1 upon the excitation of T1 may be ascribed to an efficient Tn→T′n proton transfer followed by Tn′→T′2 relaxation and T′2→S′1 reverse intersystem crossing.

Membrane-type 1 matrix metalloproteinase that is associated with the proteolytic activation of progelatinase A was expressed as a recombinant fusion protein in Escherichia coli. The recombinant enzyme cleaved the propeptide sequence of gelatinase A in a sequence-specific manner. A mutant progelatinase A that has a substitution of Asn(66)-Leu to Ile-Val was not processed at all. The processing was blocked by tissue inhibitor of metalloproteinases-2 or BB-94 but not by tissue inhibitor of metalloproteinases-1. Thus, membrane-type 1 matrix metalloproteinase is a direct activator of progelatinase A without requiring additional proteases.

Sub-microsecond time-resolved infrared spectroscopy has been used to investigate the ground-state relaxation process following the excited-state proton transfer in 2-(2′-naphthyl)-3-hydroxychromone in chloroform. Two transient species with decay times of 5.3 μs (1270 and 1230–1260 cm−1) and 500–600 μs (1220–1240 cm−1) were observed. These transient species seem to be attributable to ground-state tautomers. This observation is consistent with those by transient absorption and two-step laser-induced fluorescence.

Intramolecular exciplex and charge transfer (CT) complex fluorescence was investigated in the bichromophoric EDA systems of 1-(1-pyrenyl)-3-(p- and m-(N,N-dimethylamino)phenyl)propanes (Py-p-DMA and Py-m-DNA) in a supersonic free jet. The UV fluorescence excitation spectrum of jet-cooled Py-p-DMA exhibits vibrational structures similar to 1-alkylpyrene, while the visible fluorescence excitation spectrum of this compound has a very broad congested band. The dispersed fluorescence indicates that two types of groundstate conformers are involved; one of them exhibits the CT complex fluorescence, and another has an excess energy dependent exciplex fluorescence. In jet-cooled Py-m-DMA, two types of vibrational structure in the excitation spectra were observed. The excitation of these band series exhibit exciplex fluorescence with a remarkably different excess vibrational energy dependence. In addition to these exciplexes, the ground-state CT complex (probably a closed form) shows a CT fluorescence similar to the exciplex. The remarkably different features of the CT complex and exciplex formations are attributable to multiconformations of these bichrompophoric EDA systems in the ground state.

Fluorescence excitation and hole burning depletion spectra of jet-cooled bichromophoric compounds, 1-(9- and 1-anthryl)-3-(m-(N,N-dimethylamino)phenyl)propanes (9-An-m-DMA and 1-An-m-DMA), indicate that two isomeric conformations of these compounds are involved in the ground state. Two distinct conformers (9a and 9b) of 9-An-m-DMA exhibit roughly equal intensity of excitation spectra, while one conformer is major (1a) and another is minor (1b) in 1-An-m-DMA. These ground-state conformers exhibit remarkably different excess vibrational energy (Delta E) dependence of the intramolecular charge transfer in the singlet excited state: the Delta E dependence of the exciplex fluorescence and decay times are considerably different between the two conformations. The facts seem attributable to the torsional conformation of the m-(N,N-dimethylamino)phenyl moiety concerning the trimethylene (An-C-1-C-2-C-3-m-DMA) of these compounds in the ground state, from which the geometrical transformations take place to the favorable conformers' for the intramolecular charge transfer.