HeliQuest α-helix
Search of putative helices with defined parameters in protein database
Results by Email ?
yes
Email:
Enter your Email address to receive your results
no
The results of your query will be available by a html file
Compute parameters of a known sequence:
here
.
Use our web server to compute sequence parameters
Physico-chemical parameters
Reference value
Hydrophobicity
<H>
0.45
Minimal <H>
Maximal <H>
Enter the minimal and maximal <H> values
Hydrophobic moment
<µH>
0.7
Minimal <µH>
Maximal <µH>
Enter the minimal and maximal <µH> values
Net charge
z
0
Minimal z
Maximal z
Enter the minimal and maximal z values
Sequence statistics
Polar amino-acid composition
Reference value
Minimal number of polar residues + glycine
8
Enter the minimal number of polar residue (EDKRSTNQH)+G
Minimal number of uncharged residue
4
SER
THR
ASN
GLN
HIS
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
Enter the minimal number of selected residue
Minimal number of glycine
1
0
1
2
3
4
5
6
7
8
Enter the minimal number of glycine
Maximal number of charged residue
3
0
1
2
3
4
5
6
7
8
9
10
11
12
Enter the maximal number of charged residue
Special residue
Is proline accepted ? (at i, i+3 / n-3, n)
yes
no
Is cysteine accepted ?
yes
no
Use geometric rules
yes
no
A specific algorithm refines the identification of well-defined amphipathic helices
DataBase
SwissProt Database
Human
Rat
Mouse
Yeast
Personnal DataBase
The personal database must be in a FASTA format
BlackList (Hypothetical, Putative, Probable)
yes
no
Elimination of protein whose designation contains one of the terms of the blacklist
Helical wheel representation
One-letter code size proportional to amino acid volume
yes
no
Rotation of the helix to align vertically the
<µH>
vector
yes
no
