Welcome to HeliQuest

HeliQuest calculates from the amino acid sequence of a helix (α-helix, 3-10 helix, 3-11 helix or π helix) its physicochemical properties and amino acid composition and uses the results to screen any databank in order to identify protein segments possessing similar features.
The server is divided into 2 interconnected modules: the sequence analysis module and the screening module for α-helices and 3-11-helices.
In addition, the mutation module, (available from the sequence analysis module), allows the user to mutate helices manually or automatically using a genetic algorithm, to create analogues with specific properties.

NEW! MODIFICATION: This module is dedicated to characterizing helices known by the user. It determines properties such as hydrophobicity, hydrophobic moment, net charge (z) and amino acid composition for several helix types (α-helix, 3-10 helix, 3-11 helix or π helix).
Note 1: The link to the screening module is available only if the user analyzes sequences with an 18 a.a. window (α-helix only).
Note 2: A sequence can be modified by the manual or GA-based mutation modules once analysed (α-helix only).

Screening α-Helix:This module allows the user to screen SwissProt databases or personal databases in order to find sequences that have the general physico-chemical features of a target α-helix sequence.

NEW TOOL! Screening 3-11 Helix: This module allows the user to screen SwissProt databases or personal databases in order to find sequences that have the general physico-chemical features of a target 3-11 helix sequence.

The organization of the server is represented below with the entries and the output files.

Please cite the following reference:
Gautier R., Douguet D., Antonny B. and Drin G. HELIQUEST: a web server to screen sequences with specific α-helical properties. Bioinformatics. 2008 Sep 15;24(18):2101-2.

Comments, feedback, bugs : Please send all remarks to:

News :2012-08-07 Update of SwissProt Databases
2011-07-05 HeliQuest version 2 with new screening module for 3-11 helix and module Analysis for several helix type (α-helix, 3-10 helix, 3-11 helix or π helix)
2011-06-24 Update of SwissProt Databases
2010-12-01 New server, more powerful and fast, Update of the SwissProt Databases
2010-02-02 Update of the SwissProt Databases
2009-04-04 Update of the SwissProt Databases
2008-09-10 Update of the SwissProt Databases
2008-07-01 HeliQuest v1.2 online