Table 1 Affinities of PDZ, PTB, FERM, SH2, and ATG8 domains as well as AP2 μ2 for the ACE2 C-terminal peptide as determined by FP.

Equilibrium dissociation constant (KD) values of the tested domains for FITC-labeled ACE2 C-terminal peptides. Indicated errors are the errors of the mean (SEM); n = 3 replicates. N.B., no or low affinity (KD >100 μM).

Peptide sequenceNameModificationKD ± SEM (μM)
ACE2796-805*
FITC-QNTDDVQTSF-COO
MAGI1 PDZ1Unphos.N.B.
NHERF3 PDZ113.9 ± 0.3
NHERF3 PDZ3N.B.
SCRIB PDZ1N.B.
SHANK1 PDZ8.3 ± 0.2
SNTA1 PDZN.B.
SNX27 PDZ4.7 ± 0.3
TAX1BP3 PDZN.B.
ACE2787–798
FITC-SKGENNPGFQNT-NH2
DOK1 PTBUnphos.N.B.
FRS2 PTBN.B.
IRS1 PTBN.B.
TLN1 PTBN.B.
TLN2 PTBN.B.
SNX17 FERM(100)†
ACE2775–790
FITC-RSGENPYASIDISKGE-NH2
AP2 μ2Unphos.(60)†
pTyr781N.B.
pSer783(30)†
FYN SH2Unphos.N.B.
pTyr7817.0 ± 0.5
pSer783N.B.
NCK1 SH2Unphos.N.B.
pTyr781N.B.
pSer783N.B.
LYN SH2Unphos.N.B.
pTyr781(60)
pSer783N.B.
MAP1LC3A ATG8Unphos.N.B.
pTyr781N.B.
pSer783N.B.
MAP1LC3B ATG8Unphos.N.B.
pTyr781N.B.
pSer783N.B.
GABARAP ATG8Unphos.N.B.
pTyr781N.B.
pSer783N.B.
GABARAPL2 ATG8Unphos.N.B.
pTyr781N.B.
pSer783N.B.

*MBP was tested as a control for binding (N.B.) due to the PDZ domains being MBP-tagged. †Values in brackets indicate estimated affinities due to incomplete saturation curves.