Alonso, L.G.; García-Alai, M.M.; Smal, C.; Centeno, J.M.; Iacono, R.; Castaño, E.; Gualfetti, P.; De Prat-Gay, G. "The HPV16 E7 Viral Oncoprotein Self-Assembles into Defined Spherical Oligomers" (2004) Biochemistry. 43(12):3310-3317
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Despite the fact that E7 is a major transforming oncoprotein in papillomavirus, its structure and precise molecular mechanism of action remain puzzling to date. E7 proteins share sequence homology and proteasome targeting properties of tumor suppressors with adenovirus E1A and SV40 T antigen, two other paradigmatic oncoproteins from DNA tumor viruses. High-risk HPV16 E7, a nonglobular dimer with some properties of intrinsically disordered proteins, is capable of undergoing pH-dependent conformational transitions that expose hydrophobic surfaces to the solvent. We found that treatment with a chelating agent produced a protein that can readily assemble into homogeneous spherical particles with an average molecular mass of 790 kDa and a diameter of 50 nm, as determined from dynamic light scattering and electron microscopy. The protein undergoes a substantial conformational transition from coil to β-sheet structure, with concomitant consolidation of tertiary structure as judged by circular dichroism and fluorescence. The assembly process is very slow, in agreement with a substantial energy barrier caused by structural rearrangements. The resulting particles are highly stable, cooperatively folded, and capable of binding both Congo Red and thioflavin T, reporters of repetitive β-sheet structures similar to those found in amyloids, although no fibrillar or insoluble material was observed under our experimental conditions.


Documento: Artículo
Título:The HPV16 E7 Viral Oncoprotein Self-Assembles into Defined Spherical Oligomers
Autor:Alonso, L.G.; García-Alai, M.M.; Smal, C.; Centeno, J.M.; Iacono, R.; Castaño, E.; Gualfetti, P.; De Prat-Gay, G.
Filiación:Instituto Leloir, Fac. de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Patricias Argentinas 435, (1405) Buenos Aires, Argentina
Departamento de Quimica Biologica, Facultad de Farmacia y Bioquimica, Universidad de Buenos Aires, Junin 956, C1113AAD, Buenos Aires, Argentina
Genencor International, Inc., 925 Page Mill Road, Palo Alto, CA 94304, United States
Palabras clave:Chelation; DNA; Hydrophobicity; Oligomers; pH; Proteins; Self assembly; Tumors; Viruses; Oncoproteins; Spherical materials; Biochemistry; congo red; oligomer; oncoprotein; protein E7; thioflavine; virus protein; virus T antigen; article; beta sheet; cancer inhibition; circular dichroism; conformational transition; DNA tumor virus; electron microscopy; fluorescence; hydrophobicity; light scattering; molecular mechanics; molecular weight; nonhuman; pH measurement; priority journal; protein assembly; protein binding; protein conformation; protein folding; protein stability; protein structure; protein tertiary structure; sequence homology; Simian virus 40; Wart virus; Casein Kinase II; Circular Dichroism; Congo Red; Dimerization; Fluorescent Dyes; Humans; Molecular Weight; Oncogene Proteins, Viral; Papillomaviridae; Phosphorylation; Protein Binding; Protein Structure, Secondary; Protein-Serine-Threonine Kinases; Solubility; Thiazoles; Virus Assembly; Zinc; Adenoviridae; DNA viruses; Human papillomavirus types; Papillomavirus; Simiae; Simian virus 40
Página de inicio:3310
Página de fin:3317
Título revista:Biochemistry
Título revista abreviado:Biochemistry
CAS:congo red, 573-58-0, 80701-77-5; thioflavine, 2390-54-7; Casein Kinase II, EC; Congo Red, 573-58-0; Fluorescent Dyes; oncogene protein E7, Human papillomavirus type 16; Oncogene Proteins, Viral; Protein-Serine-Threonine Kinases, EC; Thiazoles; thioflavin T, 2390-54-7; Zinc, 7440-66-6


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---------- APA ----------
Alonso, L.G., García-Alai, M.M., Smal, C., Centeno, J.M., Iacono, R., Castaño, E., Gualfetti, P.,..., De Prat-Gay, G. (2004) . The HPV16 E7 Viral Oncoprotein Self-Assembles into Defined Spherical Oligomers. Biochemistry, 43(12), 3310-3317.
---------- CHICAGO ----------
Alonso, L.G., García-Alai, M.M., Smal, C., Centeno, J.M., Iacono, R., Castaño, E., et al. "The HPV16 E7 Viral Oncoprotein Self-Assembles into Defined Spherical Oligomers" . Biochemistry 43, no. 12 (2004) : 3310-3317.
---------- MLA ----------
Alonso, L.G., García-Alai, M.M., Smal, C., Centeno, J.M., Iacono, R., Castaño, E., et al. "The HPV16 E7 Viral Oncoprotein Self-Assembles into Defined Spherical Oligomers" . Biochemistry, vol. 43, no. 12, 2004, pp. 3310-3317.
---------- VANCOUVER ----------
Alonso, L.G., García-Alai, M.M., Smal, C., Centeno, J.M., Iacono, R., Castaño, E., et al. The HPV16 E7 Viral Oncoprotein Self-Assembles into Defined Spherical Oligomers. Biochemistry. 2004;43(12):3310-3317.