1
|
Insights into the Structures of Bilirubin and Biliverdin from Vibrational and Electronic Circular Dichroism: History and Perspectives. Molecules 2023; 28:molecules28062564. [PMID: 36985535 PMCID: PMC10054127 DOI: 10.3390/molecules28062564] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 03/06/2023] [Accepted: 03/08/2023] [Indexed: 03/14/2023] Open
Abstract
In this work we review research activities on a few of the most relevant structural aspects of bilirubin (BR) and biliverdin (BV). Special attention is paid to the exocyclic C=C bonds being in mostly Z rather than E configurations, and to the overall conformation being essentially different for BR and BV due to the presence or absence of the double C=C bond at C-10. In both cases, racemic mixtures of each compound of either M or P configuration are present in achiral solutions; however, imbalance between the two configurations may be easily achieved. In particular, results based on chiroptical spectroscopies, both electronic and vibrational circular dichroism (ECD and VCD) methods, are presented for chirally derivatized BR and BV molecules. Finally, we review deracemization experiments monitored with ECD data from our lab for BR in the presence of serum albumin and anesthetic compounds.
Collapse
|
2
|
Ghidinelli S, Abbate S, Mazzeo G, Boiadjiev SE, Lightner DA, Longhi G. Biliverdin chiral derivatives as chiroptical switches for pH and metal cation sensing. Phys Chem Chem Phys 2021; 23:20138-20151. [PMID: 34551042 DOI: 10.1039/d1cp02571f] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
A series of six optically active derivatives of the bile pigment biliverdin, namely (βS,β'S)-dimethylmesobiliverdin-XIIIα, cyclic esters of linear diols [HO(CH2)nOH] where n = 1-6, have been investigated by vibrational circular dichroism (VCD) and density functional theory (DFT) calculations. The results were correlated with the length (n) of the diester belt, the verdin helicity and an M ⇄ P conformational equilibrium - as previously shown by electronic circular dichroism (ECD). Furthermore, ECD spectra have been found to be quite sensitive to solvent nature and pH. TD-DFT calculations of the protonated/deprotonated verdins with n = 1 and 2 diester belts respectively have allowed one, moreover, to explain the spectroscopic data in terms of a change in the M ⇄ P equilibrium. Finally, the set of investigated compounds, together with other chirally functionalized "non-belted" biliverdin analogs, has also been found to be sensitive to the presence of metal ions, with which the verdins chelate. On the basis of ECD and VCD data, we propose that the spectroscopic changes observed are consistent with self-association (dimerization) of the verdin molecules promoted by the metal cations, as bolstered by DFT calculations, and for which a dimerization constant of 73 000 M-1 is evaluated. We envision the use of current chiroptical spectroscopies in connection with chiral biliverdin derivatives as natural sensors or probes of the micro-environmental conditions, such as pH or the presence of metal ions.
Collapse
Affiliation(s)
- Simone Ghidinelli
- Università di Brescia, Dipartimento di Medicina Molecolare e Traslazionale, Viale Europa 11, 25123 Brescia, Italy.
| | - Sergio Abbate
- Università di Brescia, Dipartimento di Medicina Molecolare e Traslazionale, Viale Europa 11, 25123 Brescia, Italy. .,Istituto Nazionale di Ottica (INO), C.N.R., Research Unit of Brescia, via Branze 45, 25123 Brescia, Italy
| | - Giuseppe Mazzeo
- Università di Brescia, Dipartimento di Medicina Molecolare e Traslazionale, Viale Europa 11, 25123 Brescia, Italy.
| | - Stefan E Boiadjiev
- Regional Health Inspectorate, 7 Prince Al. Battenberg I Str., 5800 Pleven, Bulgaria
| | - David A Lightner
- Chemistry Department, University of Nevada, Reno, NV, 89557, USA
| | - Giovanna Longhi
- Università di Brescia, Dipartimento di Medicina Molecolare e Traslazionale, Viale Europa 11, 25123 Brescia, Italy. .,Istituto Nazionale di Ottica (INO), C.N.R., Research Unit of Brescia, via Branze 45, 25123 Brescia, Italy
| |
Collapse
|
3
|
Ghidinelli S, Longhi G, Mazzeo G, Abbate S, Boiadjiev SE, Lightner DA. On the aggregation of bilirubinoids in solution as evidenced by VCD and ECD spectroscopy and DFT calculations. Chirality 2017; 30:19-28. [PMID: 29083054 DOI: 10.1002/chir.22776] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2017] [Revised: 09/20/2017] [Accepted: 10/01/2017] [Indexed: 11/11/2022]
Abstract
Vibrational and electronic circular dichroism (VCD and ECD) spectra of 3 optically active bilirubin analogs with propionic acid groups replaced by (1) 1-(S)-methylpropyl groups, (2) 3-acetoxy-1-(S)-methylpropyl groups, and (3) 1-(S)-2-(R)-dimethyl-2-(methoxycarbonyl)ethyl groups have been recorded at different concentrations in chloroform. The aliphatic chains attached to C-8 and C-12 of the 3 chosen mesobilirubins were modified so as to possess no OH group. The variation of the VCD spectra with concentration is consistent with the formation of dimers at high concentration. Density functional theory and time-dependent density functional theory calculations on monomeric and dimeric forms support such a conclusion. Comparing with previous VCD (ECD) and IR (UV) studies of other mesobilirubin molecules, it is concluded that here, the key feature for aggregation is the missing OH groups on the propionic acid chains. The latter, in synergy with the polar groups of lactam moieties, appear to be involved in intramolecular phenomena and thus favor monomeric forms. Investigation of ECD and UV spectra of the same compounds in mixed DMSO/chloroform solutions provide further clues to the proposed picture.
Collapse
Affiliation(s)
- Simone Ghidinelli
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy
| | - Giovanna Longhi
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy
| | - Giuseppe Mazzeo
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy
| | - Sergio Abbate
- Dipartimento di Medicina Molecolare e Traslazionale, Università di Brescia, Brescia, Italy
| | - Stefan E Boiadjiev
- Department of Chemistry and Biochemistry, Medical University-Pleven, Pleven, Bulgaria
| | - David A Lightner
- Department of Chemistry, University of Nevada, Reno, Nevada, USA
| |
Collapse
|
4
|
Boiadjiev SE, Lightner DA. DIPYRRINONES-CONSTITUENTS OF THE PIGMENTS OF LIFE. A REVIEW. ORG PREP PROCED INT 2006. [DOI: 10.1080/00304940609355999] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
|
5
|
Synthesis of a New Lipophilic Bilirubin. Conformation, Transhepatic Transport and Glucuronidation. Tetrahedron 2000. [DOI: 10.1016/s0040-4020(00)00710-9] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
6
|
Boiadjiev SE, Lightner DA. On the aggregation of bilirubins using vapor pressure osmometry. J Heterocycl Chem 2000. [DOI: 10.1002/jhet.5570370431] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
|
7
|
Cunningham O, Dunne A, Sabido P, Lightner D, Mantle TJ. Studies on the specificity of the tetrapyrrole substrate for human biliverdin-IXalpha reductase and biliverdin-IXbeta reductase. Structure-activity relationships define models for both active sites. J Biol Chem 2000; 275:19009-17. [PMID: 10858451 DOI: 10.1074/jbc.275.25.19009] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A comparison of the initial rate kinetics for human biliverdin-IXalpha reductase and biliverdin-IXbeta reductase with a series of synthetic biliverdins with propionate side chains "moving" from a bridging position across the central methene bridge (alpha isomers) to a "gamma-configuration" reveals characteristic behavior that allows us to propose distinct models for the two active sites. For human biliverdin-IXalpha reductase, as previously discussed for the rat and ox enzymes, it appears that at least one "bridging propionate" is necessary for optimal binding and catalytic activity, whereas two are preferred. All other configurations studied were substrates for human biliverdin-IXalpha reductase, albeit poor ones. In the case of mesobiliverdin-XIIIalpha, extending the propionate side chains to hexanoate resulted in a significant loss of activity, whereas the butyrate derivative retained high activity. For human biliverdin-IXalpha reductase, we suggest that a pair of positively charged side chains play a key role in optimally binding the IXalpha isomers. In the case of human biliverdin-IXbeta reductase, the enzyme cannot tolerate even one propionate in the bridging position, suggesting that two negatively charged residues on the enzyme surface may preclude productive binding in this case. The flavin reductase activity of biliverdin-IXbeta reductase is potently inhibited by mesobiliverdin-XIIIalpha and protohemin, which is consistent with the hypothesis that the tetrapyrrole and flavin substrate bind at a common site.
Collapse
Affiliation(s)
- O Cunningham
- Department of Biochemistry, Trinity College, Dublin 2, Ireland and the Departments of Chemistry & Biochemistry, University of Nevada, Reno, Nevada 89557-0020, USA
| | | | | | | | | |
Collapse
|
8
|
Chen Q, Huggins MT, Lightner DA, Norona W, McDonagh AF. Synthesis of a 10-Oxo-Bilirubin: Effects of the Oxo Group on Conformation, Transhepatic Transport, and Glucuronidation. J Am Chem Soc 1999. [DOI: 10.1021/ja991814m] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Qingqi Chen
- Contribution from the Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020, and G.I. Unit and the Liver Center, University of California, San Francisco, California 94143-0538
| | - Michael T. Huggins
- Contribution from the Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020, and G.I. Unit and the Liver Center, University of California, San Francisco, California 94143-0538
| | - David A. Lightner
- Contribution from the Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020, and G.I. Unit and the Liver Center, University of California, San Francisco, California 94143-0538
| | - Wilma Norona
- Contribution from the Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020, and G.I. Unit and the Liver Center, University of California, San Francisco, California 94143-0538
| | - Antony F. McDonagh
- Contribution from the Department of Chemistry, University of Nevada, Reno, Nevada 89557-0020, and G.I. Unit and the Liver Center, University of California, San Francisco, California 94143-0538
| |
Collapse
|
9
|
Boiadjiev SE, Lightner DA. Intramolecular hydrogen bonding and its influence on conformation. Circular dichroism of chiral bilirubin analogs. ACTA ACUST UNITED AC 1999. [DOI: 10.1016/s0957-4166(99)00254-2] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
|
10
|
Boiadjiev SE, Lightner DA. Synthesis and conformational analysis of a chiral fluorinated bilirubin analog lacking carboxyl groups. J Heterocycl Chem 1999. [DOI: 10.1002/jhet.5570360424] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
11
|
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]
|
12
|
Kar AK, Lightner DA. Synthesis and properties of bilirubin analogs with conformation-perturbing C(10) tert-butyl and adamantyl groups. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00769-8] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
13
|
Kar AK, Lightner DA. Synthesis of bilin-1,19-diones and biladiene-ac-1,19-diones with c(10) adamantyl andtert-butyl groups. J Heterocycl Chem 1998. [DOI: 10.1002/jhet.5570350404] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
|
14
|
Kar AK, Lightner DA. Synthesis and properties of C(10) isopropyl and isopropylidene analogs of bilirubin. Tetrahedron 1998. [DOI: 10.1016/s0040-4020(98)00254-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
|