International Journal of Peptides

Research Article

In Vitro Selection of Cathepsin E-Activity-Enhancing Peptide Aptamers at Neutral pH

Table 2

CatE-activating peptides (at neutral pH) obtained from the primary library (A) and the secondary library (B) selections.
NameAmino acid sequence (N→C)Size (a.a.)pIHydropathy (GRAVYd)Activities (%)KD
Adpa A b s y
(A) Primary library selection
P1 (p2006)VGCDFMYV83.81.3 1 1 8 ± 3 . 2 1 2 9 ± 1 0 N. A. (~10−5)c
P2 (p2005)KGPPPCPC88.2−0.7 1 2 8 ± 2 0 1 1 0 ± 4
P3 (p3006)IEGRVGCDFMYVG134.20.5 1 3 0 ± 1 0 1 3 0 ± 5 3 . 3 4 × 1 0 − 7
(B) Secondary library selection
S1 (p4035)SPIISHIVGCDPPSCG165.30.5 1 6 0 ± 2 0 ——
S2 (p4043)PGIKPPPCIIIIG138.61.07 1 8 0 ± 1 0 1 4 4 . 5 ± 1 1 N. A.c
S3 (p4038)IGCEERSFPNIIIIIG164.30.9 2 6 0 ± 1 0 1 6 8 ± 3 3 . 8 9 × 1 0 − 7
aAdp is the activity measured using the in vitro translated peptide.
bAsy is the activity measured using the chemically synthesized peptide. For detail, see [18].
cNot accurate; SPR-measured repeatedly but the values obtained were not sufficiently reliable. A rough estimation is given in the parenthesis.
dGrand average of hydropathy value (source: http://www.bioinformatics.org/sms2/protein_gravy.html).