TY - JOUR
T1 - Protein-protein interaction heterogeneity of plasma apolipoprotein A1 in nephrotic syndrome
AU - Santucci, Laura
AU - Candiano, Giovanni
AU - Petretto, Andrea
AU - Pavone, Barbara
AU - Bruschi, Maurizio
AU - Gusmano, Rosanna
AU - Federici, Giorgio
AU - Urbani, Andrea
AU - Ghiggeri, Gian Marco
PY - 2011/3/1
Y1 - 2011/3/1
N2 - Apolipoprotein A1 (apoA1) is a component of the high density lipoproteins (HDL) that regulates the transport of cholesterol between the liver and peripheral cells and modulates the removal of any excess of cholesterol from membranes. Any variation in apoA1 composition may modify the plasma lipid profile and be involved in atherogenesis. We investigated apoA1 composition in plasma of 6 children with nephrotic syndrome, a condition characterized by high levels of cholesterol in plasma and by a high risk to develop atherosclerosis. Non-denaturing two-dimensional electrophoresis (Nat/SDS-PAGE), mass spectrometry, western blot and pull down experiments were done to characterize proteins and define putative interactions. ApoA1 was resolved in 12 variants, 6 of which had a slightly lower molecular weight (18-19 KDa) and migrated on the same axes of the β chain of haptoglobin (Hp). Low molecular weight apoA1 were observed in carriers of different Hp haplotypes (including one homozygous for the rare ββα1α1) ruling out any contaminant effect of co-migration of apoA1 with Hp α2 chain. Overall, apoA1 isoforms were much more present in plasma of nephrotic patients compared to a normal profile. These findings show that apoA1 plasma in nephrotic syndrome is heterogeneous in terms of molecular weight. Low molecular weight fragments lack internal structural domains and likely form macro-aggregates with Hp. Fragmentation and transport of apoA1 may be involved in the general disorder of lipid metabolism that characterizes nephrotic syndrome.
AB - Apolipoprotein A1 (apoA1) is a component of the high density lipoproteins (HDL) that regulates the transport of cholesterol between the liver and peripheral cells and modulates the removal of any excess of cholesterol from membranes. Any variation in apoA1 composition may modify the plasma lipid profile and be involved in atherogenesis. We investigated apoA1 composition in plasma of 6 children with nephrotic syndrome, a condition characterized by high levels of cholesterol in plasma and by a high risk to develop atherosclerosis. Non-denaturing two-dimensional electrophoresis (Nat/SDS-PAGE), mass spectrometry, western blot and pull down experiments were done to characterize proteins and define putative interactions. ApoA1 was resolved in 12 variants, 6 of which had a slightly lower molecular weight (18-19 KDa) and migrated on the same axes of the β chain of haptoglobin (Hp). Low molecular weight apoA1 were observed in carriers of different Hp haplotypes (including one homozygous for the rare ββα1α1) ruling out any contaminant effect of co-migration of apoA1 with Hp α2 chain. Overall, apoA1 isoforms were much more present in plasma of nephrotic patients compared to a normal profile. These findings show that apoA1 plasma in nephrotic syndrome is heterogeneous in terms of molecular weight. Low molecular weight fragments lack internal structural domains and likely form macro-aggregates with Hp. Fragmentation and transport of apoA1 may be involved in the general disorder of lipid metabolism that characterizes nephrotic syndrome.
UR - http://www.scopus.com/inward/record.url?scp=79951615809&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=79951615809&partnerID=8YFLogxK
U2 - 10.1039/c0mb00127a
DO - 10.1039/c0mb00127a
M3 - Article
C2 - 21416664
AN - SCOPUS:79951615809
VL - 7
SP - 659
EP - 666
JO - Molecular BioSystems
JF - Molecular BioSystems
SN - 1742-206X
IS - 3
ER -