1
|
Vreman HJ, Kourula S, Jašprová J, Ludvíková L, Klán P, Muchová L, Vítek L, Cline BK, Wong RJ, Stevenson DK. The effect of light wavelength on in vitro bilirubin photodegradation and photoisomer production. Pediatr Res 2019; 85:865-873. [PMID: 30710116 DOI: 10.1038/s41390-019-0310-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/09/2018] [Revised: 01/11/2019] [Accepted: 01/16/2019] [Indexed: 11/09/2022]
Abstract
BACKGROUND The action spectrum for bilirubin photodegradation has been intensively studied. However, questions still remain regarding which light wavelength most efficiently photodegrades bilirubin. In this study, we determined the in vitro effects of different irradiation wavelength ranges on bilirubin photodegradation. METHODS In our in vitro method, normalized absolute irradiance levels of 4.2 × 1015 photons/cm2/s from light-emitting diodes (ranging from 390-530 nm) and 10-nm band-pass filters were used to irradiate bilirubin solutions (25 mg/dL in 4% human serum albumin). Bilirubin and its major photoisomer concentrations were determined; the half-life time of bilirubin (t1/2) was calculated for each wavelength range, and the spectral characteristics for bilirubin photodegradation products were obtained for key wavelengths. RESULTS The in vitro photodegradation of bilirubin at 37 °C decreased linearly as the wavelength was increased from 390 to 500 nm with t1/2 decreasing from 63 to 17 min, respectively. At 460 ± 10 nm, a significantly lower rate of photodegradation and thus higher t1/2 (31 min) than that at 500 nm (17 min) was demonstrated. CONCLUSION In our system, the optimum bilirubin photodegradation and lumirubin production rates occurred between 490 and 500 nm. Spectra shapes were remarkably similar, suggesting that lumirubin production was the major process of bilirubin photodegradation.
Collapse
Affiliation(s)
- Hendrik J Vreman
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA.
| | - Stephanie Kourula
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - Jana Jašprová
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic
| | - Lucie Ludvíková
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Petr Klán
- Department of Chemistry and RECETOX, Faculty of Science, Masaryk University, Kamenice 5, 625 00, Brno, Czech Republic
| | - Lucie Muchová
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic
| | - Libor Vítek
- Institute of Medical Biochemistry and Laboratory Diagnostics, 1st Faculty of Medicine, Charles University, Kateřinská 32, 120 00, Prague, Czech Republic.
| | - Benjamin K Cline
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - Ronald J Wong
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| | - David K Stevenson
- Department of Pediatrics, Stanford University School of Medicine, 300 Pasteur Drive, Room S214, Stanford, CA, 94305, USA
| |
Collapse
|
2
|
Carreira-Blanco C, Singer P, Diller R, Luis Pérez Lustres J. Ultrafast deactivation of bilirubin: dark intermediates and two-photon isomerization. Phys Chem Chem Phys 2016; 18:7148-55. [DOI: 10.1039/c5cp06971h] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
The Franck-Condon state A couples to the dark intermediate B, which shows tight molecular skeleton and distorted hydrogen bonding. B deactivates with nearly 100% efficiency. 2-Photon excitation at 400 nm triggers Z,E isomerization efficiently.
Collapse
Affiliation(s)
- Carlos Carreira-Blanco
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Department of Physical Chemistry
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| | - Patrick Singer
- Fachbereich Physik
- Technische Universität Kaiserslautern
- D-67663 Kaiserslautern
- Germany
| | - Rolf Diller
- Fachbereich Physik
- Technische Universität Kaiserslautern
- D-67663 Kaiserslautern
- Germany
| | - J. Luis Pérez Lustres
- Centro Singular de Investigación en Química Biolóxica e Materiais Moleculares (CIQUS) and Department of Physical Chemistry
- Universidade de Santiago de Compostela
- E-15782 Santiago de Compostela
- Spain
| |
Collapse
|
4
|
Khan MA, Kumar Y, Tayyab S. Bilirubin binding properties of pigeon serum albumin and its comparison with human serum albumin. Int J Biol Macromol 2002; 30:171-8. [PMID: 12063119 DOI: 10.1016/s0141-8130(02)00017-x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
Binding of bilirubin (BR) to pigeon serum albumin (PgSA) was studied by absorption, fluorescence and CD spectroscopy and results were compared with those obtained with human serum albumin (HSA). PgSA was found to be structurally similar to HSA as judged by near- and far-UV CD spectra. However, PgSA lacks tryptophan. Binding of BR to PgSA showed relatively weaker interaction compared to HSA in terms of binding affinity, induced red shift in the absorption spectrum of BR and CD spectral characteristics of BR-albumin complexes. Photoirradiation results of BR-albumin complexes also showed PgSA-bound BR more labile compared to HSA-bound BR.
Collapse
Affiliation(s)
- Mateen A Khan
- Interdisciplinary Biotechnology Unit, Aligarh Muslim University, Aligarh 202 002, India
| | | | | |
Collapse
|
5
|
Yasuda S, Itoh S, Imai T, Isobe K, Onishi S. Cyclobilirubin formation by in vitro photoirradiation with neonatal phototherapy light. Pediatr Int 2001; 43:270-5. [PMID: 11380923 DOI: 10.1046/j.1442-200x.2001.01398.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
BACKGROUND The main mechanism of phototherapy for neonatal hyperbilirubinemia is the production and excretion of (EZ)- and (EE)-cyclobilirubin (4E,15Z- and 4E,15E-cyclobilirubin). Thus, the clinical efficacy of the light source for phototherapy must be evaluated by cyclobilirubin formation from (ZZ)-bilirubin in in vitro photoirradiation. METHODS In the present study, we investigated the in vitro production pattern of bilirubin photoisomers by phototherapy light from the bilirubin-human serum albumin complex. RESULTS No clear difference was found in the curves relative to (ZZ)-bilirubin and its photoisomers under aerobic and anaerobic conditions. The ratio of (EZ)-cyclobilirubin to (ZZ)-bilirubin increased proportionately to the dose of irradiating light and no photoequilibrium state was observed analogous to that found in configurational photoisomerization. The concentration of (EZ)- and (EE)-cyclobilirubin increased proportionately with the grade of the percentage decrease in A(460 nm) from 0 to 23%. With a percentage decrease in A(460 nm) of 23% or more, the cyclobilirubin concentrations reached a steady state. The reason for this appears to be that the concentration of (ZZ)-bilirubin, a substrate for photoisomers, dropped below 1 mg/100 mL. Biliverdin was produced only in trace amounts. However, the absorption at 520--700 nm increased after a percentage decrease in A(460 nm) of more than 23%. CONCLUSIONS The results of the present study show that little bilirubin photooxidation occurred with in vitro aerobic photoirradiation. Before the concentration of cyclobilirubin reaches a steady state, it is theoretically valid to use the percentage decrease in A(460 nm) for the evaluation of the clinical efficacy of the light source.
Collapse
Affiliation(s)
- S Yasuda
- Department of Pediatrics, Kagawa Medical University, Kagawa, Japan
| | | | | | | | | |
Collapse
|
6
|
Khan MM, Muzammil S, Tayyab S. Role of salt bridge(s) in the binding and photoconversion of bilirubin bound to high affinity site on human serum albumin. BIOCHIMICA ET BIOPHYSICA ACTA 2000; 1479:103-13. [PMID: 11004533 DOI: 10.1016/s0167-4838(00)00050-9] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
The role of salt bridge(s) (between epsilon-NH(2) groups of lysine residues of human serum albumin (HSA) and carboxyl groups of bilirubin) in the binding and photoconversion of bilirubin bound to high affinity site on HSA was investigated by covalent modification of approximately 20% internal (buried) lysine residues of HSA with acetic anhydride, succinic anhydride and O-methylisourea and white light irradiation of their complexes with bilirubin. The different HSA derivatives, namely, acetylated HSA (aHSA), succinylated HSA (sHSA) and guanidinated HSA (gHSA), thus obtained, were found to be homogeneous with respect to charge and size and characterized in detail in terms of mean residue ellipticity, Stokes radius, tryptophan fluorescence, bilirubin binding and the photochemistry of their complexes with bilirubin. All the three derivatives retained helical contents and molecular size (Stokes radius) similar to HSA except for sHSA which showed a slight increase in the Stokes radius from 3.56 to 3.64 nm. Further, fluorescence properties of aHSA and sHSA were also found to be different from HSA and gHSA. Based on difference spectral change, fluorescence quenching and fluorescence enhancement results of bilirubin bound to HSA and its derivatives, nearly 46 and 48% reduction in bilirubin binding was observed in the case of aHSA and sHSA, respectively. Both aHSA and sHSA showed a decrease of 8- and 10-fold, respectively, in association constant compared to native HSA. Although the bisignate circular dichroism (CD) spectra of an equimolar (1:1) bilirubin-HSA complex was retained by all three HSA derivatives, the intensity of both positive and negative CD Cotton effects decreased significantly in both aHSA and sHSA. gHSA which retained net charge identical to native HSA, showed little decrease in bilirubin binding and the intensity of bisignate CD Cotton effects. The photochemical reaction of bilirubin bound to aHSA and sHSA produced opposite results to those observed with HSA and gHSA. A brief (2 min) irradiation of an equimolar complex of bilirubin with both aHSA and sHSA accompanied a rapid shift (14-15 nm) in the absorption spectrum of the bound pigment towards the blue region and almost complete elimination of negative CD Cotton effects while only moderately affecting the magnitude of positive CD Cotton effects. On the other hand, similar treatment of the complexes of bilirubin with HSA and gHSA did not show any change in the absorption spectrum, only a slight decrease in the intensity of both positive and negative CD Cotton effects was observed. The fluorescence intensity of bilirubin bound to HSA and gHSA was increased upon irradiation with white light and after 30 min it was nearly twice the value observed at 0 min irradiation. Interestingly, no change in the fluorescence intensity of bilirubin bound either to aHSA or sHSA was observed upon irradiation, even on increasing the duration of irradiation to 1 h. Taken together, the results on fluorescence quenching, fluorescence enhancement, CD spectral changes and visible absorption spectroscopy suggest that salt bridge(s) of the type (-COO(-).(+)H(3)N-) in which the epsilon-NH(2) group(s) contributed by lysine residues, are not only involved in the enantioselective binding of bilirubin but also in the stereospecific photoisomerization of bilirubin bound to a high affinity site on HSA.
Collapse
Affiliation(s)
- M M Khan
- Protein and Enzyme Laboratory, Interdisciplinary Biotechnology Unit, Aligarh Muslim University, 202002 (U.P.), Aligarh, India
| | | | | |
Collapse
|
7
|
Kanna Y, Arai T, Tokumaru K. Effect of the Binding Sites of Human Serum Albumin on the Efficiency and Photostationary State Isomer Ratios of the Photoisomerization of Bilirubin. BULLETIN OF THE CHEMICAL SOCIETY OF JAPAN 1994. [DOI: 10.1246/bcsj.67.2758] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
|
9
|
Knobloch E, Mandys F, Hodr R, Hujer R, Mader R. Study of the mechanism of the photoisomerization and photooxidation of bilirubin using a model for the phototherapy of hyperbilirubinemia. JOURNAL OF CHROMATOGRAPHY 1991; 566:89-99. [PMID: 1885724 DOI: 10.1016/0378-4347(91)80113-q] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Liquid chromatography was employed for a study of photochemical degradation of bilirubin in the complex with human albumin, using a model system in the presence of riboflavin. The concentrations of bilirubin, the photoisomers and biliverdin were monitored. The reaction mechanism was verified using a quantified mathematical model and was represented by a reaction scheme. Photoisomerization is the initial process, followed by photooxidation to degradation products of the tetrapyrrole skeleton, with formation of biliverdin as an intermediate. The blood of newborns that were irradiated for treatment of hyperbilirubinemia was studied for the sake of comparison. The effect of some biochemically important substances was followed, in view of possible inhibition of the processes. The experimental results demonstrate that riboflavin acts as a catalyst, even at the concentrations typical for its occurrence in blood. The results are discussed from the point of view of the mechanism of bilirubin degradation during phototherapy.
Collapse
Affiliation(s)
- E Knobloch
- Institute for the Care of Mother and Child, Prague, Czechoslovakia
| | | | | | | | | |
Collapse
|