Porphyrin-induced protein structural alterations of heme enzymes
Some alterations in the protein structure of d-aminolevulinic acid dehydratase (ALA-D) and porphobilinogen deaminase (PBG-D) induced by uroporphyrin (URO) and prototoporphyrin (PROTO) have been observed previously. To obtain further evidence of these phenomena, the absorption and fluorescence spectr...
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todo:paper_13572725_v29_n8-9_p1113_Afonso2023-10-03T16:10:27Z Porphyrin-induced protein structural alterations of heme enzymes Afonso, S.G. De Salamanca, R.E. Batlle, A.M.D.C. Enzgme structure Molecular alterations Photodynamic action Porphyrins aminolevulinic acid heme porphyrin protoporphyrin article chemical structure controlled study enzyme structure nonhuman photodynamics protein structure Amino Acids Animals Cattle Heme Hydroxymethylbilane Synthase Liver Porphobilinogen Synthase Porphyrins Protoporphyrins Spectrometry, Fluorescence Spectrophotometry Sulfhydryl Compounds Ultraviolet Rays Uroporphyrins Bovinae Some alterations in the protein structure of d-aminolevulinic acid dehydratase (ALA-D) and porphobilinogen deaminase (PBG-D) induced by uroporphyrin (URO) and prototoporphyrin (PROTO) have been observed previously. To obtain further evidence of these phenomena, the absorption and fluorescence spectra of ALA-D and PBG-D and the total protein content of sulfhydryl and free amino groups were analyzed after exposure of the enzymes to URO I and PROTO IX. ALA-D and PBG-D were partially purified from bovine liver and exposed to URO I or PROTO IX, both in the dark and under UV light. All experiments were performed in the enzyme solutions after removing the porphyrins. Absorbance spectra changes in the region of 220-300 nm were registered, indicating the interaction of the porphyrins with the molecular structure of the enzymes. The main changes in the fluorescence spectra were observed in the spectral region of 555 nm, and only slight modifications in the spectral region of 340-360 nm; moreover, alterations were stronger upon UV irradiation and in the presence of URO P when compared with darkness and PROTO IX. Variations in total SH groups would suggest the formation of disulfur bridges induced by URO I and the rupture of some SS groups induced by PROTO IX. The effect of porphyrins on free amino groups would reflect a combination of cross-linking and fragmentation of proteins. Structural changes were observed when the enzymes were exposed to the porphyrin both in the dark or under UV light; however, they were stronger in tile latter condition. These results suggest that porphyrins per se could act directly on the protein structure and that this action would be enhanced upon UV irradiation. JOUR info:eu-repo/semantics/openAccess http://creativecommons.org/licenses/by/2.5/ar http://hdl.handle.net/20.500.12110/paper_13572725_v29_n8-9_p1113_Afonso |
| institution |
Universidad de Buenos Aires |
| institution_str |
I-28 |
| repository_str |
R-134 |
| collection |
Biblioteca Digital - Facultad de Ciencias Exactas y Naturales (UBA) |
| topic |
Enzgme structure Molecular alterations Photodynamic action Porphyrins aminolevulinic acid heme porphyrin protoporphyrin article chemical structure controlled study enzyme structure nonhuman photodynamics protein structure Amino Acids Animals Cattle Heme Hydroxymethylbilane Synthase Liver Porphobilinogen Synthase Porphyrins Protoporphyrins Spectrometry, Fluorescence Spectrophotometry Sulfhydryl Compounds Ultraviolet Rays Uroporphyrins Bovinae |
| spellingShingle |
Enzgme structure Molecular alterations Photodynamic action Porphyrins aminolevulinic acid heme porphyrin protoporphyrin article chemical structure controlled study enzyme structure nonhuman photodynamics protein structure Amino Acids Animals Cattle Heme Hydroxymethylbilane Synthase Liver Porphobilinogen Synthase Porphyrins Protoporphyrins Spectrometry, Fluorescence Spectrophotometry Sulfhydryl Compounds Ultraviolet Rays Uroporphyrins Bovinae Afonso, S.G. De Salamanca, R.E. Batlle, A.M.D.C. Porphyrin-induced protein structural alterations of heme enzymes |
| topic_facet |
Enzgme structure Molecular alterations Photodynamic action Porphyrins aminolevulinic acid heme porphyrin protoporphyrin article chemical structure controlled study enzyme structure nonhuman photodynamics protein structure Amino Acids Animals Cattle Heme Hydroxymethylbilane Synthase Liver Porphobilinogen Synthase Porphyrins Protoporphyrins Spectrometry, Fluorescence Spectrophotometry Sulfhydryl Compounds Ultraviolet Rays Uroporphyrins Bovinae |
| description |
Some alterations in the protein structure of d-aminolevulinic acid dehydratase (ALA-D) and porphobilinogen deaminase (PBG-D) induced by uroporphyrin (URO) and prototoporphyrin (PROTO) have been observed previously. To obtain further evidence of these phenomena, the absorption and fluorescence spectra of ALA-D and PBG-D and the total protein content of sulfhydryl and free amino groups were analyzed after exposure of the enzymes to URO I and PROTO IX. ALA-D and PBG-D were partially purified from bovine liver and exposed to URO I or PROTO IX, both in the dark and under UV light. All experiments were performed in the enzyme solutions after removing the porphyrins. Absorbance spectra changes in the region of 220-300 nm were registered, indicating the interaction of the porphyrins with the molecular structure of the enzymes. The main changes in the fluorescence spectra were observed in the spectral region of 555 nm, and only slight modifications in the spectral region of 340-360 nm; moreover, alterations were stronger upon UV irradiation and in the presence of URO P when compared with darkness and PROTO IX. Variations in total SH groups would suggest the formation of disulfur bridges induced by URO I and the rupture of some SS groups induced by PROTO IX. The effect of porphyrins on free amino groups would reflect a combination of cross-linking and fragmentation of proteins. Structural changes were observed when the enzymes were exposed to the porphyrin both in the dark or under UV light; however, they were stronger in tile latter condition. These results suggest that porphyrins per se could act directly on the protein structure and that this action would be enhanced upon UV irradiation. |
| format |
JOUR |
| author |
Afonso, S.G. De Salamanca, R.E. Batlle, A.M.D.C. |
| author_facet |
Afonso, S.G. De Salamanca, R.E. Batlle, A.M.D.C. |
| author_sort |
Afonso, S.G. |
| title |
Porphyrin-induced protein structural alterations of heme enzymes |
| title_short |
Porphyrin-induced protein structural alterations of heme enzymes |
| title_full |
Porphyrin-induced protein structural alterations of heme enzymes |
| title_fullStr |
Porphyrin-induced protein structural alterations of heme enzymes |
| title_full_unstemmed |
Porphyrin-induced protein structural alterations of heme enzymes |
| title_sort |
porphyrin-induced protein structural alterations of heme enzymes |
| url |
http://hdl.handle.net/20.500.12110/paper_13572725_v29_n8-9_p1113_Afonso |
| work_keys_str_mv |
AT afonsosg porphyrininducedproteinstructuralalterationsofhemeenzymes AT desalamancare porphyrininducedproteinstructuralalterationsofhemeenzymes AT batlleamdc porphyrininducedproteinstructuralalterationsofhemeenzymes |
| _version_ |
1807320667548286976 |