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Gryczynski Z, Kimball J, Fudala R, Chavez J, Ceresa L, Szabelski M, Borejdo J, Gryczynski I. Photophysical properties of 2-Phenylindole in poly (vinyl alcohol) film at room temperature. Enhanced phosphorescence anisotropy with direct triplet state excitation. Methods Appl Fluoresc 2020; 8:014008. [PMID: 31851960 DOI: 10.1088/2050-6120/ab6366] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
We report the spectral properties of 2-Phenylindole (2PI) embedded in rigid poly (vinyl alcohol) (PVA) film. The 2PI in PVA film shows relatively strong and structured fluorescence with a maximum at 370 nm and surprisingly strong room temperature phosphorescence with an emission maximum of about 500 nm. The dye is highly immobilized in the polymer matrix, thus presenting high fluorescence anisotropy in an isotropic film of about 0.3 at room temperature. The 2-Phenylindole phosphorescence excited in the usual way through the electronic singlet state excitation (S0 → S1 absorption) results in a very low, near zero anisotropy. We now report that we can directly excite the dye to the triplet state T1 and observe high phosphorescence anisotropy similar to the fluorescence anisotropy. The extinction coefficient for S0 → T1 absorption in the PVA matrix is unusually high- only about 3 orders of magnitude lower than S0 → S1 absorption. We consider this direct excitation to indole's triplet state a very significant finding that may lead to many practical applications. The unusually long-wavelength of excitation around 400 nm, much above typical UV absorption, results in a high phosphorescence anisotropy. This provides a new way to study rotational motion of larger biological objects in the microsecond time scale not accessible through typical fluorescence studies.
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Affiliation(s)
- Z Gryczynski
- Department of Microbiology, Immunology and Genetics, Center for Fluorescence Technologies and Nanomedicine, University of North Texas Health Science Center, Fort Worth, TX 76107, United States of America. Department of Physics and Astronomy, Texas Christian University, Fort Worth, TX 76129, United States of America
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Duggal D, Nagwekar J, Rich R, Huang W, Midde K, Fudala R, Das H, Gryczynski I, Szczesna-Cordary D, Borejdo J. Effect of a myosin regulatory light chain mutation K104E on actin-myosin interactions. Am J Physiol Heart Circ Physiol 2015; 308:H1248-57. [PMID: 25770245 DOI: 10.1152/ajpheart.00834.2014] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2014] [Accepted: 03/03/2015] [Indexed: 11/22/2022]
Abstract
Familial hypertrophic cardiomyopathy (FHC) is the most common cause of sudden cardiac death in young individuals. Molecular mechanisms underlying this disorder are largely unknown; this study aims at revealing how disruptions in actin-myosin interactions can play a role in this disorder. Cross-bridge (XB) kinetics and the degree of order were examined in contracting myofibrils from the ex vivo left ventricles of transgenic (Tg) mice expressing FHC regulatory light chain (RLC) mutation K104E. Because the degree of order and the kinetics are best studied when an individual XB makes a significant contribution to the overall signal, the number of observed XBs in an ex vivo ventricle was minimized to ∼20. Autofluorescence and photobleaching were minimized by labeling the myosin lever arm with a relatively long-lived red-emitting dye containing a chromophore system encapsulated in a cyclic macromolecule. Mutated XBs were significantly better ordered during steady-state contraction and during rigor, but the mutation had no effect on the degree of order in relaxed myofibrils. The K104E mutation increased the rate of XB binding to thin filaments and the rate of execution of the power stroke. The stopped-flow experiments revealed a significantly faster observed dissociation rate in Tg-K104E vs. Tg-wild-type (WT) myosin and a smaller second-order ATP-binding rate for the K104E compared with WT myosin. Collectively, our data indicate that the mutation-induced changes in the interaction of myosin with actin during the contraction-relaxation cycle may contribute to altered contractility and the development of FHC.
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Affiliation(s)
- D Duggal
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
| | - J Nagwekar
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
| | - R Rich
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
| | - W Huang
- Department of Molecular & Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida; and
| | - K Midde
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
| | - R Fudala
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
| | - H Das
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and Department of Pharmacology and Neuroscience, Institute of Aging and Alzheimer's Disease Research, Institute of Cancer Research, Fort Worth, Texas
| | - I Gryczynski
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
| | - D Szczesna-Cordary
- Department of Molecular & Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, Florida; and
| | - J Borejdo
- Department of Cell Biology & Immunology and Center for Commercialization of Fluorescence Technologies, University of North Texas, Health Science Center, Fort Worth, Texas; and
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Nagwekar J, Duggal D, Rich R, Raut S, Fudala R, Gryczynski I, Gryczynski Z, Borejdo J. The spatial distribution of actin and mechanical cycle of myosin are different in right and left ventricles of healthy mouse hearts. Biochemistry 2014; 53:7641-9. [PMID: 25488019 PMCID: PMC4262935 DOI: 10.1021/bi501175s] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
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The contraction of the right ventricle
(RV) expels blood into the
pulmonary circulation, and the contraction of the left ventricle (LV)
pumps blood into the systemic circulation through the aorta. The respective
afterloads imposed on the LV and RV by aortic and pulmonary artery
pressures create very different mechanical requirements for the two
ventricles. Indeed, differences have been observed in the contractile
performance between left and right ventricular myocytes in dilated
cardiomyopathy, in congestive heart failure, and in energy usage and
speed of contraction at light loads in healthy hearts. In spite of
these functional differences, it is commonly believed that the right
and left ventricular muscles are identical because there were no differences
in stress development, twitch duration, work performance, or power
among the RV and LV in dogs. This report shows that on a mesoscopic
scale [when only a few molecules are studied (here three to six molecules
of actin) in ex vivo ventricular myofibrils], the
two ventricles in rigor differ in the degree of orientational disorder
of actin within in filaments and during contraction in the kinetics
of the cross-bridge cycle.
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Affiliation(s)
- J Nagwekar
- Department of Cell Biology and Center for Fluorescence Technology and Nanomedicine, University of North Texas Health Science Center , 3500 Camp Bowie Boulevard, Fort Worth, Texas 76107, United States
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Raut SL, Fudala R, Rich R, Kokate RA, Chib R, Gryczynski Z, Gryczynski I. Long lived BSA Au clusters as a time gated intensity imaging probe. Nanoscale 2014; 6:2594-7. [PMID: 24469148 PMCID: PMC4643945 DOI: 10.1039/c3nr05692a] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
The work presented here reports the use of long lifetime (>1 μs) BSA Au clusters as a cellular/tissue, time gated, intensity imaging probe. By collecting the emission signal 50 ns post excitation, one can off-gate the intense auto-fluorescence background, thereby greatly enhancing the clarity/specificity in fluorescence imaging.
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Affiliation(s)
- S L Raut
- Center for Commercialization of Fluorescence Technologies, Department of Cell Biology and Immunology, University of North Texas Health Science Center, 3500 Camp Bowie Blvd., Fort Worth, Texas 76107, USA.
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Kondakova AN, Linder B, Fudala R, Senchenkova SN, Moll H, Shashkov AS, Kaca W, Zähringer U, Knirel YA. New structures of the O-specific polysaccharides of proteus. 4. Polysaccharides containing unusual acidic N-acyl derivatives of 4-amino-4,6-dideoxy-D-glucose. Biochemistry (Mosc) 2005; 69:1034-43. [PMID: 15521818 DOI: 10.1023/b:biry.0000043546.46903.32] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The structures of the O-polysaccharides of the lipopolysaccharides of Proteus mirabilis O7 and O49 were determined by chemical methods, mass spectrometry, including MS/MS, and NMR spectroscopy, including experiments run in an H2O/D2O mixture to reveal correlations for NH protons. The O-polysaccharides were found to contain N-carboxyacetyl (malonyl) and N-(3-carboxypropanoyl) (succinyl) derivatives of 4-amino-4,6-dideoxyglucose (4-amino-4-deoxyquinovose, Qui4N), respectively. The behavior of Qui4N derivatives with the dicarboxylic acids under conditions of acid hydrolysis and methanolysis was studied using GLC-MS.
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Affiliation(s)
- A N Kondakova
- Zelinsky Institute of Organic Chemistry, Russian Academy of Sciences, Moscow, 119991, Russia
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