Abstract
Insulin degrading enzyme (IDE) is believed to be the major enzyme that metabolizes insulin and has been implicated in the degradation of a number of other bioactive peptides, including amyloid beta peptide (A?), glucagon, amylin, and atrial natriuretic peptide. IDE is activated toward some substrates by both peptides and polyanions/anions, possibly representing an important control mechanism and a potential therapeutic target. A binding site for the polyanion ATP has previously been defined crystallographically, but mutagenesis studies suggest that other polyanion binding modes likely exist on the same extended surface that forms one wall of the substrate-binding chamber. Here we use a computational approach to define three potential ATP binding sites and mutagenesis and kinetic studies to confirm the relevance of these sites. Mutations were made at four positively charged residues (Arg 429, Arg 431, Arg 847, Lys 898) within the polyanion-binding region, converting them to polar or hydrophobic residues. We find that mutations in all three ATP binding sites strongly decrease the degree of activation by ATP and can lower basal activity and cooperativity. Computational analysis suggests conformational changes that result from polyanion binding as well as from mutating residues involved in polyanion binding. These findings indicate the presence of multiple polyanion binding modes and suggest the anionbinding surface plays an important conformational role in controlling IDE activity.
| Original language | English (US) |
|---|---|
| Article number | 133114 |
| Journal | PLoS One |
| Volume | 10 |
| Issue number | 7 |
| DOIs | |
| State | Published - Jul 17 2015 |
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ASJC Scopus subject areas
- Agricultural and Biological Sciences(all)
- Biochemistry, Genetics and Molecular Biology(all)
- Medicine(all)
Cite this
An extended polyanion activation surface in insulin degrading enzyme. / Song, Eun Suk; Ozbil, Mehmet; Zhang, Tingting; Sheetz, Michael; Lee, David; Tran, Danny; Li, Sheng; Prabhakar, Rajeev; Hersh, Louis B.; Rodgers, David W.
In: PLoS One, Vol. 10, No. 7, 133114, 17.07.2015.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - An extended polyanion activation surface in insulin degrading enzyme
AU - Song, Eun Suk
AU - Ozbil, Mehmet
AU - Zhang, Tingting
AU - Sheetz, Michael
AU - Lee, David
AU - Tran, Danny
AU - Li, Sheng
AU - Prabhakar, Rajeev
AU - Hersh, Louis B.
AU - Rodgers, David W.
PY - 2015/7/17
Y1 - 2015/7/17
N2 - Insulin degrading enzyme (IDE) is believed to be the major enzyme that metabolizes insulin and has been implicated in the degradation of a number of other bioactive peptides, including amyloid beta peptide (A?), glucagon, amylin, and atrial natriuretic peptide. IDE is activated toward some substrates by both peptides and polyanions/anions, possibly representing an important control mechanism and a potential therapeutic target. A binding site for the polyanion ATP has previously been defined crystallographically, but mutagenesis studies suggest that other polyanion binding modes likely exist on the same extended surface that forms one wall of the substrate-binding chamber. Here we use a computational approach to define three potential ATP binding sites and mutagenesis and kinetic studies to confirm the relevance of these sites. Mutations were made at four positively charged residues (Arg 429, Arg 431, Arg 847, Lys 898) within the polyanion-binding region, converting them to polar or hydrophobic residues. We find that mutations in all three ATP binding sites strongly decrease the degree of activation by ATP and can lower basal activity and cooperativity. Computational analysis suggests conformational changes that result from polyanion binding as well as from mutating residues involved in polyanion binding. These findings indicate the presence of multiple polyanion binding modes and suggest the anionbinding surface plays an important conformational role in controlling IDE activity.
AB - Insulin degrading enzyme (IDE) is believed to be the major enzyme that metabolizes insulin and has been implicated in the degradation of a number of other bioactive peptides, including amyloid beta peptide (A?), glucagon, amylin, and atrial natriuretic peptide. IDE is activated toward some substrates by both peptides and polyanions/anions, possibly representing an important control mechanism and a potential therapeutic target. A binding site for the polyanion ATP has previously been defined crystallographically, but mutagenesis studies suggest that other polyanion binding modes likely exist on the same extended surface that forms one wall of the substrate-binding chamber. Here we use a computational approach to define three potential ATP binding sites and mutagenesis and kinetic studies to confirm the relevance of these sites. Mutations were made at four positively charged residues (Arg 429, Arg 431, Arg 847, Lys 898) within the polyanion-binding region, converting them to polar or hydrophobic residues. We find that mutations in all three ATP binding sites strongly decrease the degree of activation by ATP and can lower basal activity and cooperativity. Computational analysis suggests conformational changes that result from polyanion binding as well as from mutating residues involved in polyanion binding. These findings indicate the presence of multiple polyanion binding modes and suggest the anionbinding surface plays an important conformational role in controlling IDE activity.
UR - http://www.scopus.com/inward/record.url?scp=84941342094&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=84941342094&partnerID=8YFLogxK
U2 - 10.1371/journal.pone.0133114
DO - 10.1371/journal.pone.0133114
M3 - Article
C2 - 26186535
AN - SCOPUS:84941342094
VL - 10
JO - PLoS One
JF - PLoS One
SN - 1932-6203
IS - 7
M1 - 133114
ER -