1
|
Laskar AA, Khan MA, Rahmani AH, Fatima S, Younus H. Thymoquinone, an active constituent of Nigella sativa seeds, binds with bilirubin and protects mice from hyperbilirubinemia and cyclophosphamide-induced hepatotoxicity. Biochimie 2016; 127:205-13. [PMID: 27265787 DOI: 10.1016/j.biochi.2016.05.020] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2016] [Accepted: 05/31/2016] [Indexed: 12/13/2022]
Abstract
Some reports indicate that thymoquinone (TQ), the main constituent of Nigella sativa seeds, is hepatoprotective. The aim of this study was to determine whether TQ is able to bind directly to bilirubin, and whether TQ or liposomal formulation of TQ (Lip-TQ) can reduce cyclophosphamide (CYP)-induced liver toxicity, serum bilirubin level in mice. The binding of TQ with bilirubin was studied by UV-VIS, fluorescence and Near-UV CD spectroscopy. Inhibition of binding of bilirubin to erythrocytes by TQ was also examined. To increase the in vivo efficacy, Lip-TQ was prepared and used against CYP-induced toxicity. The protective role of TQ or Lip-TQ against CYP-induced toxicity was assessed by determining the liver function parameters, the levels of superoxide dismutase (SOD) and catalase (CAT), and histological studies. It was found that TQ binds to bilirubin and significantly inhibits the binding of bilirubin to erythrocytes. Lip-TQ (10 mg/kg) significantly reduced the levels of aspartate transaminase (AST) from 254 ± 48 to 66 ± 18 IU/L (P < 0.001), alanine transaminase (ALT) from 142 ± 28 to 47.8 ± 16 IU/L (P < 0.05) and serum bilirubin from 2.8 ± 0.50 to 1.24 ± 0.30 mg/dl (P < 0.05). Treatment with Lip-TQ reduced the CYP-induced inflammation and hemorrhage in liver tissues. Moreover, treatment with free or Lip-TQ protected the activity of SOD and CAT in CYP-injected mice. Therefore, TQ can reduce the level of bilirubin in systemic circulation in disease conditions that lead to hyperbilirubinemia and liver toxicity and hence may be used as a supplement in the treatment of liver ailments.
Collapse
Affiliation(s)
- Amaj A Laskar
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India
| | - Masood A Khan
- College of Applied Medical Sciences, Qassim University, Buraydah, 51452, Saudi Arabia
| | - Arshad H Rahmani
- College of Applied Medical Sciences, Qassim University, Buraydah, 51452, Saudi Arabia
| | - Sana Fatima
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India
| | - Hina Younus
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh, 202002, India.
| |
Collapse
|
2
|
Sorrenti A, Altieri B, Ceccacci F, Di Profio P, Germani R, Giansanti L, Savelli G, Mancini G. Deracemization of bilirubin as the marker of the chirality of micellar aggregates. Chirality 2011; 24:78-85. [DOI: 10.1002/chir.21026] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Accepted: 08/11/2011] [Indexed: 11/10/2022]
|
3
|
Zsila F. Circular dichroism spectroscopy is a sensitive tool for investigation of bilirubin-enzyme interactions. Biomacromolecules 2010; 12:221-7. [PMID: 21141881 DOI: 10.1021/bm1012103] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Noncovalent complex formation of unconjugated bilirubin with various enzymes has been demonstrated by measuring induced circular dichroism (ICD) peaks associated with the pigment VIS absorption band. Preferential binding of the P- or M-helical conformer of bilirubin to dehydrogenases, catalase, alkaline phosphatase, and α-chymotrypsin is responsible for the characteristic exciton CD couplet that undergoes remarkable changes upon the addition of enzymatic cofactors (NADH, AMP) and an inhibitor (acridine). Alterations of the ICD spectra refer to a direct binding competition between bilirubin and NADH for a common binding site on alcohol dehydrogenase and catalase, suggesting a potential mechanism for the inhibitory effect of BR reported on NAD(P)H dependent enzymes. NADH and bilirubin form a ternary complex with glutamate dehydrogenase indicated by peculiar CD spectral changes that are proposed to be generated by allosteric mechanism. α-chymotrypsin binds bilirubin in its catalytic site, as indicated by CD displacement experiments performed with the competitive inhibitor acridine. Surprisingly, the closely related trypsin does not induce any CD signal with bilirubin. Taking into consideration the clinically relevant but controversial and poorly understood areas of bilirubin biochemistry, the fast and simple CD spectroscopic approach presented here may help to unfold diverse physiological and pathophysiological roles of BR on a molecular level.
Collapse
Affiliation(s)
- Ferenc Zsila
- Department of Molecular Pharmacology, Institute of Biomolecular Chemistry, Chemical Research Center, H-1025 Budapest, Pusztaszeri út 59-67, Hungary.
| |
Collapse
|
4
|
Iwase T, Kusaka T, Itoh S. (EZ)-Cyclobilirubin formation from bilirubin in complex with serum albumin derived from various species. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY B-BIOLOGY 2010; 98:138-43. [DOI: 10.1016/j.jphotobiol.2009.11.012] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/19/2009] [Revised: 06/23/2009] [Accepted: 11/26/2009] [Indexed: 10/20/2022]
|
5
|
Bernardini C, D'Arrigo P, Elemento G, Mancini G, Servi S, Sorrenti A. The posssible role of enantiodiscrimination in bilirubin toxicity. Chirality 2009; 21:87-91. [DOI: 10.1002/chir.20610] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
6
|
Ceccacci F, Giansanti L, Mortera SL, Mancini G, Sorrenti A, Villani C. Enantiodiscrimination of bilirubin-IXα enantiomers in biomembrane models: Has chirality a role in bilirubin toxicity? Bioorg Chem 2008; 36:252-4. [DOI: 10.1016/j.bioorg.2008.05.001] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 04/30/2008] [Accepted: 05/02/2008] [Indexed: 11/30/2022]
|
7
|
Bombelli C, Bernardini C, Elemento G, Mancini G, Sorrenti A, Villani C. Concentration as the Switch for Chiral Recognition in Biomembrane Models. J Am Chem Soc 2008; 130:2732-3. [DOI: 10.1021/ja710687e] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Cecilia Bombelli
- CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy, and Dipartimento di Chimica and Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
| | - Carlotta Bernardini
- CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy, and Dipartimento di Chimica and Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
| | - Gioia Elemento
- CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy, and Dipartimento di Chimica and Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
| | - Giovanna Mancini
- CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy, and Dipartimento di Chimica and Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
| | - Alessandro Sorrenti
- CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy, and Dipartimento di Chimica and Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
| | - Claudio Villani
- CNR, Istituto di Metodologie Chimiche and Dipartimento di Chimica “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy, and Dipartimento di Chimica and Dipartimento di Studi di Chimica e Tecnologia delle Sostanze Biologicamente Attive, Università degli Studi di Roma “La Sapienza”, P.le A. Moro 5, 00185 Roma, Italy
| |
Collapse
|
8
|
Bile pigment complexes with cyclodextrins: electronic and vibrational circular dichroism study. ACTA ACUST UNITED AC 2007. [DOI: 10.1016/j.tetasy.2007.08.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
|
9
|
Molecular basis of the Cotton effects induced by the binding of curcumin to human serum albumin. ACTA ACUST UNITED AC 2003. [DOI: 10.1016/s0957-4166(03)00486-5] [Citation(s) in RCA: 94] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
|
10
|
Zsila F, Bikádi Z, Simonyi M. Unique, pH-dependent biphasic band shape of the visible circular dichroism of curcumin-serum albumin complex. Biochem Biophys Res Commun 2003; 301:776-82. [PMID: 12565848 DOI: 10.1016/s0006-291x(03)00030-5] [Citation(s) in RCA: 65] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
Interaction between the plant derived polyphenolic type curcumin molecule having anticarcinogenic, antiinflammatory, and antioxidant activities, and human serum albumin was studied at different pH values by circular dichroism (CD) and electronic absorption spectroscopy. The weak, induced CD spectrum of curcumin-HSA complex measured at pH 7.4 in the visible spectral region shows striking changes upon alkalization; CD spectra collected between pH 7.7 and 9.3 exhibit characteristic, oppositely signed CD band pair according to the visible absorption band of HSA-bound curcumin. At 0.3 curcumin/HSA molar ratio, typical molar CD values are Delta epsilon (496.6nm)+40M(-1)cm(-1) and Delta epsilon (426.8nm)-40M(-1)cm(-1), respectively (pH 9.0, t=37 degrees C). The induced optical activity is attributed to a bent, right-handed chiral conformation of the HSA-bound curcumin molecule within which intramolecular exciton coupling occurs between the electric dipole transition moments of the dissymmetrically juxtaposed feruloyl chromophores. Deprotonation of phenolic OH group(s) of curcumin seems to be the reason leading to the conformational alteration of HSA-bound curcumin.
Collapse
Affiliation(s)
- Ferenc Zsila
- Department of Molecular Pharmacology, Institute of Chemistry, Chemical Research Center, Budapest, Hungary.
| | | | | |
Collapse
|
11
|
Affiliation(s)
- D J Hill
- Department of Chemistry and Materials Science & Engineering, The Beckman Institute for Advanced Science and Technology, University of Illinois at Urbana-Champaign, Urbana, Illinois 61801, USA
| | | | | | | | | |
Collapse
|
12
|
Boiadjiev SE, Lightner DA. Optical activity and stereochemistry of linear oligopyrroles and bile pigments. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0957-4166(99)00037-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
13
|
Boiadjiev SE, Lightner DA. Altering the Acidity and Solution Properties of Bilirubin. Methoxy and Methylthio Substituents. J Org Chem 1998; 63:6220-6228. [PMID: 11672252 DOI: 10.1021/jo980740e] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Substitution of electron-withdrawing groups at the alpha-position of an aliphatic carboxylic acid can be expected to increase the acidity of the acid. Methoxy and methylthio groups are especially effective; they increase the acidity of acetic acid by approximately 1.1 pK(a) units. Bilirubin, the water-insoluble pigment of jaundice, has two propionic acids, and an alpha-methoxy or alpha-methylthio substituent in each propionic acid can be expected to lower the pK(a) similarly and thus alter its solubility properties. (A previously synthesized analogue, alpha,alpha'-difluororubin (4), is soluble in water.) Two new analogues of bilirubin, alpha,alpha'-dimethoxyrubin (1) and alpha,alpha'-bis(methylthio)rubin (2), have been synthesized, separated into diastereomers, and analyzed. The isomers are shown by NMR to adopt intramolecularly hydrogen-bonded ridge-tile-shaped conformations. Like bilirubin, both 1 and 2 are insoluble in water. Unlike bilirubin, 1 is soluble in dilute aqueous bicarbonate, but 2 is insoluble, which would not be predicted from the expectation that 1 and 2 have the same pK(a). The data hint at a much larger steric size of SCH(3) relative to OCH(3).
Collapse
|
14
|
Boiadjiev SE, Pfeiffer WP, Lightner DA. Synthesis and stereochemistry of bilirubin analogs lacking carboxylic acids. Tetrahedron 1997. [DOI: 10.1016/s0040-4020(97)01066-1] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
15
|
Patra SK, Pal MK. Dichroic Probe of the Equilibrium Constant of the Distribution of Bilirubin to Human and Bovine Serum Albumins. JOURNAL OF MACROMOLECULAR SCIENCE PART A-PURE AND APPLIED CHEMISTRY 1997. [DOI: 10.1080/10601329708010027] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
|
16
|
Patra SK, Pal MK. Spectroscopic probes of the individual and combined effects of Triton X-100 and chloroform on serum albumins and serum-albumin.bilirubin complexes. EUROPEAN JOURNAL OF BIOCHEMISTRY 1997; 246:658-64. [PMID: 9219523 DOI: 10.1111/j.1432-1033.1997.t01-1-00658.x] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The effects of the non-ionic surfactant Triton X-100 on the biphasic induced CD spectra of bilirubin complexes of human and bovine serum albumins (HSA and BSA) are divergent. While Triton X-100 inverts the induced CD spectrum of HSA.bilirubin, this surfactant enhances the ellipticity values of induced CD of BSA.bilirubin without inversion. The effect of Triton X-100 on the characteristic ultraviolet-CD spectra of the albumins are similar; both the albumins are denatured from their native globular structures. The anionic surfactant SDS, unlike non-ionic Triton X-100, dislodges the ligand from its protein complexes, indicating that both electrostatic and hydrophobic forces are involved in binding of bilirubin to the albumins. The aprotic solvent chloroform inverts the biphasic induced CD spectra of HSA.bilirubin and BSA.bilirubin, whereas CHCl3 has relatively little effect on the ultraviolet CD spectra of the albumins. The combined effect of Triton X-100 and CHCl3 shows that the effect of CHCl3 predominates over that of Triton X-100. The perturbing effects of Triton X-100 and CHCl3 on the CD or induced CD spectra of the proteins or their bilirubin complexes are reversible, and independent of the order in which components were added. The observations suggest that the denaturation of the albumins by Triton X-100 or solvation of CHCl3 within albumins markedly alter the internal topography or dynamics of the receptor sites, triggering alterations of the chirality of the bound pigment in sign and/or magnitude.
Collapse
Affiliation(s)
- S K Patra
- Department of Biochemistry and Biophysics, University of Kalyani, India
| | | |
Collapse
|
17
|
Bauman D, Killet C, Boiadjiev SE, Lightner DA, Schönhofer A, Kuball HG. Linear and Circular Dichroism Spectroscopic Study of β,β‘-Dimethylmesobilirubin-XIIIα Oriented in a Nematic Liquid Crystal. ACTA ACUST UNITED AC 1996. [DOI: 10.1021/jp960508h] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Danuta Bauman
- Institute of Physics, Poznań University of Technology, Piotrowo 3, 60-965 Poznań, Poland; Fachbereich Chemie, Universität Kaiserslautern, D-67653 Kaiserslautern, Germany; Department of Chemistry, University of Nevada, Reno, Nevada 89577-0020; and Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Claudia Killet
- Institute of Physics, Poznań University of Technology, Piotrowo 3, 60-965 Poznań, Poland; Fachbereich Chemie, Universität Kaiserslautern, D-67653 Kaiserslautern, Germany; Department of Chemistry, University of Nevada, Reno, Nevada 89577-0020; and Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Stefan E. Boiadjiev
- Institute of Physics, Poznań University of Technology, Piotrowo 3, 60-965 Poznań, Poland; Fachbereich Chemie, Universität Kaiserslautern, D-67653 Kaiserslautern, Germany; Department of Chemistry, University of Nevada, Reno, Nevada 89577-0020; and Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - David A. Lightner
- Institute of Physics, Poznań University of Technology, Piotrowo 3, 60-965 Poznań, Poland; Fachbereich Chemie, Universität Kaiserslautern, D-67653 Kaiserslautern, Germany; Department of Chemistry, University of Nevada, Reno, Nevada 89577-0020; and Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Alfred Schönhofer
- Institute of Physics, Poznań University of Technology, Piotrowo 3, 60-965 Poznań, Poland; Fachbereich Chemie, Universität Kaiserslautern, D-67653 Kaiserslautern, Germany; Department of Chemistry, University of Nevada, Reno, Nevada 89577-0020; and Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| | - Hans-Georg Kuball
- Institute of Physics, Poznań University of Technology, Piotrowo 3, 60-965 Poznań, Poland; Fachbereich Chemie, Universität Kaiserslautern, D-67653 Kaiserslautern, Germany; Department of Chemistry, University of Nevada, Reno, Nevada 89577-0020; and Institut für Theoretische Physik, Technische Universität Berlin, D-10623 Berlin, Germany
| |
Collapse
|
18
|
|
19
|
Claret J, Ibars O, Lang K, Trull FR, Lightner DA. Electrochemical reduction of the biliverdin-serum albumin complex as monitored by absorption and circular dichroism spectroscopy. BIOCHIMICA ET BIOPHYSICA ACTA 1995; 1243:221-9. [PMID: 7873566 DOI: 10.1016/0304-4165(94)00131-g] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
The cathodic reduction at the mercury electrode of a biliverdin IX alpha-serum albumin complex at physiological pH in an aqueous buffer containing percentages of DMSO ranging from 4% to 20% is studied by cyclic voltametry and controlled potential coulometry. The progression of pigment disappearance and the (stereochemical) nature of the product are monitored by chromatography, UV-visible absorption and circular dichroism spectroscopy. Upon reduction, albumin-bound biliverdin IX alpha, with a slight preference for the P-helicity, affords the corresponding bound bilirubin IX alpha -with an M-chirality conformation. The complex is reduced at -0.64 V (vs. SCE; 8% DMSO), only a little shifted compared to reduction of free biliverdin IX alpha under the same conditions. In contrast, an analogous bilirubin IX alpha-serum albumin complex is essentially inert towards cathodic reduction under conditions where free bilirubin IX alpha is reduced, indicating a better shielding by the protein of the bilirubin IX alpha molecule from the electrode surface. The presence of relative position (as in the biliverdins IX alpha and XIII alpha) or absence (as in mesobiliverdin IX alpha) of vinyl groups in the pigment does not have a significant effect upon its electroreduction behaviour, indicating that the process is not sensitive to the subtle differences imposed by vinyl groups upon the structure of the corresponding biliverdin-albumin complexes.
Collapse
Affiliation(s)
- J Claret
- Departament de Química Física, Facultat de Química, Universitat de Barcelona, Catalunya, Spain
| | | | | | | | | |
Collapse
|
20
|
Hwang KO, Anstine D, Lightner DA. Synthesis and properties of bilirubin analogs with N,N-methylene bridges. Tetrahedron 1994. [DOI: 10.1016/s0040-4020(01)89607-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
|
21
|
D'Alagni M, D'Archivio AA, Giglio E. On the interaction of polypeptides with bile salts or bilirubin-IX alpha. Biopolymers 1993; 33:1553-65. [PMID: 8218923 DOI: 10.1002/bip.360331006] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Abstract
Aqueous solutions formed by polypeptides, simple models of proteins, and bile salts (sodium cholate and deoxycholate, NaC and NaDC, respectively) or bilirubin-IX alpha (BR) have been studied by CD measurements. They could mimic more complicated biliary systems, thus supplying a possible interpretation of the behavior of some amino acid residues in the biliary proteins. The aggregation of NaDC and NaC in water can be monitored by CD measurements. Bile salts, in submicellar and micellar form, stabilize poly(L-Lys) (PLL) in alpha-helical conformation. The alpha-helix content increases with increasing bile salt concentration and ionic strength. NaDC seems to be a slightly better stabilizing agent of the alpha-helix conformation than NaC. Models characterized by hydrogen bonds between bile salts and PLL are proposed, also resorting to previous data available on the systems formed by NaDC and poly(L-Leu-L-Leu-L-Lys) (PLLL) or poly(L-Leu-L-Leu-L-Asp) (PLLA). Binding of BR to PLL, poly(D-Lys), poly(L-Glu), PLLL, and PLLA in water has been investigated by CD spectra in order to clarify the nature of the association complexes and the mechanism of the BR enantioselective complexation. Potential energy calculations provide binding models capable of explaining the enantioselective ability of the PLL and PLLL alpha-helices toward the left- and right-handed enantiomer of BR, respectively. BR is bound to -NH2 groups of PLL and PLLL lying on a right- and left-handed spiral, respectively. These results, together with those formerly obtained for some bile salts-BR systems, indicate that the selectivity originates from a binding that involves large regions of the BR molecule and gives rise, very probably, to moderate conformational changes from the "ridge tile" structure observed in the crystals. In some cases van der Waals forces can play a crucial role in the chiral recognition of bilirubin. Moreover, possible interaction models of BR with human serum albumin are proposed on the basis of a recent x-ray crystal structure of the protein.
Collapse
Affiliation(s)
- M D'Alagni
- Dipartimento di Chimica, Università di Roma La Sapienza, Italy
| | | | | |
Collapse
|
22
|
Krois D. Investigation on intermolecular forces between bile pigments and polar model compounds mimicking the chromophore - protein interactions in biliproteins. Tetrahedron 1993. [DOI: 10.1016/s0040-4020(01)81905-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
|
23
|
Trull FR, Ibars O, Lightner DA. Conformation inversion of bilirubin formed by reduction of the biliverdin-human serum albumin complex: evidence from circular dichroism. Arch Biochem Biophys 1992; 298:710-4. [PMID: 1416999 DOI: 10.1016/0003-9861(92)90470-h] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
As shown by circular dichroism spectroscopy, biliverdin preferentially adopts an M-helicity conformation on human serum albumin in aqueous buffer, pH 7.5, whereas biliverdin exhibits only a weak preference for the P-helicity conformation on bovine serum albumin at the same pH. Upon rapid reduction of the complexes with sodium borohydride, P-helicity bilirubin-IX alpha is obtained on the human albumin complex, and M-helicity bilirubin-IX alpha is obtained on the bovine serum albumin complex. Thus, biliverdin in effect undergoes an inversion of chirality upon reduction. Since the reduction did not afford a rubin with the same helicity as that of the verdin, the observations point to a hitherto undetected conformational mobility of albumin-bound bilirubin.
Collapse
Affiliation(s)
- F R Trull
- Departament de Química Orgànica, Universitat de Barcelona, Catalunya, Spain
| | | | | |
Collapse
|
24
|
Chiefari J, Person RV, Lightner DA. Synthesis and conformation of a bilirubin analog with propionic acid side chains extended to undecanoic acid. Tetrahedron 1992. [DOI: 10.1016/s0040-4020(01)89846-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
25
|
|
26
|
Agati G, Fusi F. New trends in photobiology (invited review). Recent advances in bilirubin photophysics. JOURNAL OF PHOTOCHEMISTRY AND PHOTOBIOLOGY. B, BIOLOGY 1990; 7:1-14. [PMID: 2125072 DOI: 10.1016/1011-1344(90)85138-m] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
The high photosensibility of bilirubin represents the main reason why neonatal jaundice is treated with light. The relaxation processes of excited bilirubin appear to be governed by complex mechanisms which are not fully known. At room temperature, radiationless channels, such as Z----E configurational photoisomerizations and internal conversions, contribute mostly to the deactivation of singlet excited bilirubin. Exciton coupling processes between the two pyrromethenone chromophores constituting the molecule may play a crucial role in bilirubin photophysics.
Collapse
Affiliation(s)
- G Agati
- Istituto di Elettronica Quantistica-CNR, Firenze, Italy
| | | |
Collapse
|
27
|
Kano K, Yoshiyasu K, Hashimoto S. Molecular Recognition by Saccharides. Asymmetric Complexation between Bilirubin and Nucleosides. CHEM LETT 1990. [DOI: 10.1246/cl.1990.21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
28
|
Gawronski J, Polonski T, Lightner D. Sulfoxides as chiral complexation agents. Conformational enantiomer resolution and induced circular dichroism of bilirubins. Tetrahedron 1990. [DOI: 10.1016/s0040-4020(01)81462-9] [Citation(s) in RCA: 29] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
|
29
|
Bouvier M, Brown GR. The induced circular dichroism of bilirubin complexed with the alpha-helix form of poly(L-lysine). BIOCHIMICA ET BIOPHYSICA ACTA 1989; 991:303-9. [PMID: 2719973 DOI: 10.1016/0304-4165(89)90120-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Binding of bilirubin by the alpha-helix conformation of poly(L-lysine) in water induces optical activity. The bisignate circular dichroism spectrum exhibits exciton bands centred at 444 nm, negative, and at 525 nm, positive. The magnitude of the induced circular dichroism depends on the concentration of total bilirubin and total lysine residues, the molar ratio of total lysine residues-to-total bilirubin molecules, the pH and the degree of polymerization of poly(L-lysine). Although bilirubin binds to the random coil conformation of poly(L-lysine), as evidence by the absorption spectrum, the complex is optically inactive. The results suggest that bilirubin binds to the poly(L-lysine) in the form of dimers and oligomers.
Collapse
Affiliation(s)
- M Bouvier
- McGill University, Department of Chemistry, Montreal, Canada
| | | |
Collapse
|
30
|
Understanding bilirubin conformation and binding. Circular dichroism of human serum albumin complexes with bilirubin and its esters. J Biol Chem 1988. [DOI: 10.1016/s0021-9258(18)37442-8] [Citation(s) in RCA: 89] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
|
31
|
Lightner DA, An JY, Pu YM. Circular dichroism of bilirubin-amine association complexes: insights into bilirubin-albumin binding. Arch Biochem Biophys 1988; 262:543-59. [PMID: 3364979 DOI: 10.1016/0003-9861(88)90406-7] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Bichromophoric (4Z, 15Z)-bilirubin-IX alpha, the yellow-orange cytotoxic pigment of jaundice, adopts either of two intramolecularly hydrogen-bonded enantiomeric conformations that are in dynamic equilibrium in solution. The addition of optically active amines induces the pigment solutions to exhibit intense bisignate circular dichroism in the region of the bilirubin long wavelength uv-visible absorption band. The most intense circular dichroism Cotton effects, (delta epsilon) approximately equal to 130, are induced by beta-arylamines and are comparable to those exhibited by bilirubin complexes with serum albumin and other proteins. Like serum albumin and other proteins, the optically active base acts as a chiral complexation agent to induce an asymmetric transformation of bilirubin, whose induced bisignate circular dichroism Cotton effect is characteristic of exciton splitting of the component pyrromethenone chromophores. The amines thus serve as chiral templates for molecular recognition, and the complementary action of the amine complexation sites provides insight into the binding forces important in protein-bilirubin heteroassociation.
Collapse
Affiliation(s)
- D A Lightner
- Department of Chemistry, University of Nevada, Reno 89557-0020
| | | | | |
Collapse
|
32
|
Lightner DA, McDonagh AF, Wijekoon W, Reisinger M. Amplification of optical activity by remote chiral functionality. Tetrahedron Lett 1988. [DOI: 10.1016/0040-4039(88)85278-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
33
|
|
34
|
Huber R, Schneider M, Mayr I, Müller R, Deutzmann R, Suter F, Zuber H, Falk H, Kayser H. Molecular structure of the bilin binding protein (BBP) from Pieris brassicae after refinement at 2.0 A resolution. J Mol Biol 1987; 198:499-513. [PMID: 3430616 DOI: 10.1016/0022-2836(87)90296-8] [Citation(s) in RCA: 179] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
The bilin binding protein (BBP) from the insect Pieris brassicae has been analysed for amino acid sequence, spectral properties and three-dimensional structure. The crystal structure that had been determined by isomorphous replacement has been refined at 2.0 A (1 A = 0.1 nm) resolution to an R-value of 0.20. The asymmetric unit contains four independent subunits of BBP. The co-ordinate differences are 0.25 A, in accord with the estimated error in co-ordinates. The polypeptide chain fold is characterized by an eight-stranded barrel. The connecting loops splay out at the upper end of the barrel and open it, whilst the lower end is closed. The overall shape resembles a calyx. The biliverdin IX gamma chromophore is located in a central cleft at the upper end of the barrel. The bilatriene moiety is in cyclic helical geometry with configuration Z,Z,Z and conformation syn,syn,syn. The geometry is in accord with the spectral properties and permits a correlation between sign of the circular dichroism bands and sense of the bilatriene helices. The fold of BBP is related to retinol binding protein (RBP), as had been recognized in the preliminary analysis, although the amino acid sequences of RBP and BBP show only 10% homology. There are large differences in the loops at the upper end of the barrel, whilst the segments of the centre and the lower end of the barrel superimpose closely. The ligands of BBP and RBP, biliverdin and retinol, respectively, are also similarly located.
Collapse
Affiliation(s)
- R Huber
- Max-Planck-Institut für Biochemie, Martinsried, BRD
| | | | | | | | | | | | | | | | | |
Collapse
|
35
|
|
36
|
|
37
|
Abstract
Complexes of bilirubin with chymotrypsin, lysozyme and apomyoglobin in neutral aqueous solution are characterized by circular dichroism spectra in the visible region. These are analogous to previously investigated bilirubin-serum albumin complexes. Ferriprotoporphyrin IX displaces bilirubin from its apomyoglobin complex.
Collapse
|
38
|
Lightner DA, Reisinger M, Landen GL. On the structure of albumin-bound bilirubin. Selective binding of intramolecularly hydrogen-bonded conformational enantiomers. J Biol Chem 1986. [DOI: 10.1016/s0021-9258(17)38489-2] [Citation(s) in RCA: 50] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022] Open
|
39
|
Bilirubin conformational enantiomer selection in sodium deoxycholate chiral micelles. ACTA ACUST UNITED AC 1985. [DOI: 10.1007/bf00657500] [Citation(s) in RCA: 25] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
|