title: Copper binding to naturally occurring, lactam form of angiogenin differs from that to recombinant protein, affecting their activity.
abstract: Angiogenin is a member of the ribonuclease family and a normal constituent of human plasma. It is one of the most potent angiogenic factors known and is overexpressed in different types of cancers. Copper is also an essential cofactor in angiogenesis and, during this process, it is mobilized from inside to outside of the cell. To date, contrasting results have been reported about copper(ii) influencing angiogenin activity. However, in these studies, the recombinant form of the protein was used. Unlike recombinant angiogenin, that contains an extra methionine with a free terminal amino group, the naturally occurring protein present in human plasma starts with a glutamine residue that spontaneously cyclizes to pyroglutamate, a lactam derivative. Herein, we report spectroscopic evidence indicating that copper(ii) experiences different coordination environments in the two protein isoforms, and affects their RNase and angiogenic activity differently. These results show how relatively small differences between recombinant and wild type proteins can result in markedly different behaviours.
authors.affiliation: Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, 56126, Pisa, Italy. lamendola@farm.unipi.it.
authors.forename: D
authors.initials: D
authors.lastname: La Mendola
authors.affiliation: Department of Chemistry, University of Bari "A. Moro", via E. Orabona 4, 70125 Bari, Italy. Fabio.arnesano@uniba.it.
authors.forename: F
authors.initials: F
authors.lastname: Arnesano
authors.affiliation: Department of Chemistry and Molecular Biology, University of Gothenburg, Medicinaregatan 9C, PO Box 462, SE-40530 Göteborg, Sweden.
authors.forename: Ö
authors.initials: Ö
authors.lastname: Hansson
authors.affiliation: Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, 56126, Pisa, Italy. lamendola@farm.unipi.it.
authors.forename: C
authors.initials: C
authors.lastname: Giacomelli
authors.affiliation: Department of Chemistry, University of Bari "A. Moro", via E. Orabona 4, 70125 Bari, Italy. Fabio.arnesano@uniba.it.
authors.forename: V
authors.initials: V
authors.lastname: Calò
authors.affiliation: Department of Chemistry, University of Bari "A. Moro", via E. Orabona 4, 70125 Bari, Italy. Fabio.arnesano@uniba.it.
authors.forename: V
authors.initials: V
authors.lastname: Mangini
authors.affiliation: Institute of Biostructure and Bioimaging, CNR, via P. Gaifami 18, 95126 Catania, Italy.
authors.forename: A
authors.initials: A
authors.lastname: Magrì
authors.affiliation: Institute of Biostructure and Bioimaging, CNR, via P. Gaifami 18, 95126 Catania, Italy.
authors.forename: F
authors.initials: F
authors.lastname: Bellia
authors.affiliation: Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, 56126, Pisa, Italy. lamendola@farm.unipi.it.
authors.forename: M L
authors.initials: ML
authors.lastname: Trincavelli
authors.affiliation: Department of Pharmacy, University of Pisa, via Bonanno Pisano 6, 56126, Pisa, Italy. lamendola@farm.unipi.it.
authors.forename: C
authors.initials: C
authors.lastname: Martini
authors.affiliation: Department of Chemistry, University of Bari "A. Moro", via E. Orabona 4, 70125 Bari, Italy. Fabio.arnesano@uniba.it.
authors.forename: G
authors.initials: G
authors.lastname: Natile
authors.affiliation: Institute of Biostructure and Bioimaging, CNR, via P. Gaifami 18, 95126 Catania, Italy.
authors.forename: E
authors.initials: E
authors.lastname: Rizzarelli
mesh_terms: D000595:Amino Acid Sequence; D001665:Binding Sites; D002942:Circular Dichroism; D003300:Copper / Q000378:metabolism*; D004578:Electron Spin Resonance Spectroscopy; D061307:Human Umbilical Vein Endothelial Cells / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D007769:Lactams / Q000378:metabolism*; D009682:Magnetic Resonance Spectroscopy; D008969:Molecular Sequence Data; D010455:Peptides / Q000737:chemistry / Q000378:metabolism; D011485:Protein Binding; D017433:Protein Structure, Secondary; D012343:RNA, Transfer / Q000378:metabolism; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism*; D012259:Ribonuclease, Pancreatic / Q000737:chemistry / Q000378:metabolism*; D012260:Ribonucleases / Q000378:metabolism
chemical_list: D007769:Lactams; D010455:Peptides; D011994:Recombinant Proteins; D003300:Copper; D012343:RNA, Transfer; D012260:Ribonucleases; C046366:angiogenin; D012259:Ribonuclease, Pancreatic