Almost 48 hours post the official release of the brand new iOS 7, and the world wild web is buzzing and bustling with tweets, “how to” articles, complaints and also praises for the face lift apple hinted toward some months ago. From my own experience, and from other millions of iPhone users, it is clear that the 7 is not presenting a revolution in comparison to its past sibling, keeping to the “close box” concept yet delivering a system which is quite robust. Even so, several features (some easily identified others not so) can be a plus for a scientist at their bench (or at their desks). I will go over some of these with the hope that it will make you do more science at the bench with your mobile.
Crystallography for beginners – part 6b – what to do when the protein doesn’t crystallize? Lysine Methylation
In the previous post I have discussed how limited proteolysis aids in protein’s fold boundaries determination and identification of the minimal crystallizeable fragments or domains. An important factor controlling protein crystallization is surface contact arrays between one molecule to another. Under most circumstances crystallographers can’t know which residue participates in surface interaction and whether this modification will aid in crystallization at all. For this reason lysine methylation, initially developed for isotope labeling of proteins, is a purely empirical method that is another avenue to check when protein doesn’t crystallize.
Crystallography for beginners – part 6a – what to do when the protein doesn’t crystallize? introduction to Limited proteolysis
I will start my “Protein crystallography rescue strategies” series with a rational biochemical approach to determine the boundaries of domains.
In previous posts I have discussed methods to grow protein crystals and how to monitor their growth. Yet, in many cases the first screen(s) trials will not yield any protein crystals. In such a case, what strategies one should explore on the path for protein crystals? In this and later posts I will discuss these rescue strategies and how they can help in improving your chance to obtain the sought protein crystal.
Crystallography for beginners – part 5 – monitoring and evaluating crystallization experiments results
So, you’ve set your first plate(s) as I have detailed in my previous post about setting up crystallization plates. That’s great, yet this is only the first half of a crystallization experiment. Now you need to monitor for crystal growth and interpret the result of the crystallization experiments so you know which future experiment to setup to obtain crystals (unless you’re lucky and already obtained a crystal in the initial experiment). It might sound like the fun part yet this step is crucial for obtaining crystals when those don’t come so easily (which is the case for most proteins).
You have purified your protein and you’re ready for your first protein crystallization experiment. In this post I will give you step by step instructions how to set your first protein crystallization experiment.