User access mode

 

Commercial/ Industrial access

Commercial or industrial users should contact the MAX IV industrial relations team.

 

Academic/ Open User Access

General

Academic users can apply twice a year for access to the FragMAX facility through regular calls for proposals at MAX IV Laboratory. FragMAX currently invites applications for projects taking place between March 2022 to August 2022. The deadline for submissions is

Sunday, October 10th 2021

Moreover, we can offer fast access to a limited number of proposals each year for time-critical projects.

European users can apply through the iNEXT discovery program at any point throughout the year.

Please note that the FragMAX team will assess the technical feasibility of each project to ensure efficient use of screening time and to maximize your chances for a successful campaign. We therefore require that you fill in a survey about your project (see “How to apply”), but we also encourage you to get in touch before you submit your application to discuss the requirements of your project (see Contact below).

Applications to the MAX IV user program need to be submitted through DUO where their scientific merit is evaluated by an independent and external panel of experts before access is granted (see “How to apply”). For applications via iNEXT Discovery, please follow the link, click “Apply for access”, then select “Fragment/Ligand Screening” and choose ”Fragment Screening, MAX IV, Lund, Sweden”.

How to apply

  1. Checkout the prerequisites for successful crystallographic fragment screening (see below)
  2. Download the project survey and send to the FragMAX team for further discussion (see Contact below).
  3. Prepare and submit your application through the MAX IV DUO system. Please note that there is currently no specific application route for FragMAX projects in DUO, i.e. you need to apply for beamtime at BioMAX:
    • Select Proposal Type: Normal (or Fast Access)
    • Select Research Area: Structural Biology
    • Select Beamlines: BioMAX
    • Describe you project as usual, but please mention FragMAX in the title or abstract

Miscellaneous

Academic experiments at FragMAX are governed by MAX IV user policies.

Contact

Prerequisites for successful crystallographic fragment screening

Crystal-based fragment screening is a straightforward process at FragMAX, but we have seen from previous experience, that project success mostly depends on the characteristics of the crystal system.  It is therefore important that the system is ready before you consider applying at FragMAX because we cannot easily extend approved proposals that fail due to technical problems. The list below gives an overview of some of the most important points to consider:

Reproducible crystallization:

Crystallographic fragment screening requires several hundred protein crystals (for fragment soaks and for establishing tolerance to organic solvents). It is therefore of utmost importance that crystals can be grown reliably and reproducibly in large quantities without needing to prepare tens of crystallization plates.

Crystallization format:

Crystal preparation at FragMAX is optimized for 3-lens SWISSCI sitting-drop crystallization plates with typical drop volumes ranging from 100 – 400 nL. We are not able to support experiments on-site that require crystallization in hanging-drop plates, 24/48-well sitting drop, or LCP plates. However, if your protein only crystallizes in these formats, we can send you a copy of our in-house developed FragMAXlib fragment library. You can then prepare the crystals in your home lab and send the frozen samples back to MAX IV for data collection and analysis.

Crystallization temperature:

We can grow crystals at 4 and 20 degrees at FragMAX, but the entire crystal preparation process can currently only be done at room temperature. It is often possible to soak and mount crystal that were grown at 4 degrees at ambient temperatures, but of course not in all cases. Please test in advance if your crystals only grow at 4 degrees and if they can tolerate being put at room temperature for prolonged periods of time without deteriorating. Please note, that as with the crystallization format, we can always send the FragMAXlib library to your home lab.

Crystal appearance:

Crystals should be robust and big(ish). While both criteria are not objective, it is obvious to most practitioners that all stages of the experiments are simpler with easy-to-handle crystals that do not fall into pieces at first sight and are of reasonable size. Crystals should have a size of 30 µm in at least of dimension and should not require special care during soaking/ mounting.

Crystal packing:

Fragments are applied through crystal soaking at FragMAX. Hence, if you know the “site of interest” of your protein, please check that this region is accessible through solvent channels and is not blocked by crystal contacts. As mentioned before, we can send you the FragMAXlib library in case you want to try co-crystallization in your home lab.

Resolution:

It is important that crystals diffract uniformly and reliably to resolutions below 2Å (ideally), but at least up to 2.8Å. Better data quality simply makes ligand identification easier, but it also increases the amount of information that be obtained from the structures.

Solvent tolerance:

The compounds from all our fragment libraries are dissolved in DMSO and the FragMAXlib library is additionally dissolved in Ethylene glycol. In a typical experiment, we would prepare a 10 – 30 % solution of each fragment with crystallization buffer and add it to the crystallization drop. Hence, crystals should show some tolerance towards these solvents and if your crystal system can cope with higher solvent concentrations, you are able to soak with higher ligand concentrations which should in principle help to identify lower affinity fragments bound to the protein. Additionally, the added solvent, combined with the low volume of crystallization solution around our loops often obviates the need for additional cryo protection. However, we are in principle able to dissolve the FragMAXlib in your crystallization buffer if your crystal system cannot tolerate either DMSO or Ethylene glycol. And we can also add an extra cryo-protection step to our crystal preparation workflow in case this is necessary. But regardless, we advise to establish the tolerance to DMSO and Ethylene glycol beforehand and also to check if solvent molecules are occupying interesting binding sites.

Diffraction behavior:

Understand your crystal system and be aware of complicating issues like twinning, pseudo-translations/ symmetry, multiple crystal forms in the same crystallization drop or susceptibility to (site-specific) radiation damage.

Finally…

We understand that science is rarely predictable, that sometimes unorthodox solutions are required and that there are many possibilities that we have not yet considered. Therefore, don’t hesitate to get in touch if there is anything you’d like to discuss, even if it does not fit the “standard” FragMAX workflow.

FragMAX infrastructure

FragMAX offers aided crystal harvesting with Crystal Shifter (OLT) integrated with our sample submission system (ISPyB) and data visualization tool (FragMAXapp).

During experiments at MAX IV, users can benefit from our facility and tools, such as High-Performance Computers,  pucks and loops.