Cunning snake venom is unraveled through protein characterization

The complex poison cocktail that a snakebite contains is what Rob Haselberg wants to analyze in detail. He is an assistant professor at the VU Department of BioAnalytical Chemistry in Amsterdam and specializes in protein characterization via capillary electrophoresis. FHI spoke to him.

By: Dimitri Reijerman

Haselberg is fond of protein-rich substances, such as snake venom: “As long as they are proteins, I want to characterize them. Proteins are complex and sometimes difficult to understand. In that respect it is a lot of fun to work with it, because there is always something new to discover. Yet, despite being partly unpredictable, proteins are still partly predictable. There are only twenty building blocks, the amino acids, and there are a limited amount of modifications.”

The research into blow poison was originally set up by a colleague of Haselberg: “My colleague, Associate Professor Jeroen Kool, has experience in researching drug metabolites. He looks for metabolites that are bioactive and therefore have their own effect. This expertise led him to explore snake venom to look for bioactive components in that venom. This research has become increasingly broader and we have started to look in more detail at different types of snake venom. And we mainly look for bioactive elements for medicines. A good example is if a snake bites you and you bleed to death, then that venom can potentially be a good blood pressure lowering agent because the venom does not clot your blood.”

Snake venom consists of hundreds to thousands of components, much of which is still unknown. “Then you get questions like: do these substances work together and what is the precise cell function? We know that it is mainly peptides and proteins, but it remains very complex,” says Haselberg.

During his research into the poison, Haselberg uses capillary electrophoresis (CE) as a separation technique to study the different proteins. He has been doing this for fifteen years and is highly specialized in this process. He briefly explains how it works: “By applying a voltage to a capillary, proteins are attracted to the positive or negative side. Each protein has its own speed of movement in this process, which not only makes protein separations possible, but also allows modifications within proteins to be separated based on their charge and size.”

Haselberg, together with colleagues, has now developed a portfolio of methods to measure snake venom via CE. In addition, the application of CE to the poison has been automated, which has increased the reliability of the analyses. “And at the same time we can draw up all kinds of profiles of snake venom,” says Haselberg. “It is interesting, for example, to see what exactly the molecular weight of those proteins is. We can also determine the isoelectric point of a protein. This determines whether they can pass through certain membranes, for example. And that CE information also works for setting up methods to better characterize them. Because before we applied CE, we used HPLC analyses. But that didn't yield great results. Now that we have mapped them better, we have also been able to optimize the HPLC methods.”

“We have now also developed a method with which we can very quickly profile snake venom, within ten minutes,” the researcher continues. “The next step we want to take now is to make a pre-separation and start looking for bioactive components again. With capillary electrophoresis we can identify these components based on certain peaks. If we know what it is, we may have a target for a drug. That would of course be very nice.”

The poison that the VU works with comes from the Liverpool School of Tropical Medicine. “They have snakes there that are being milked,” Haselberg says. “And we also receive poison through other partners, but as freeze-dried powder.”

Haselberg has now investigated almost all types of snake venom. His conclusion: “Each type of poison is unique. We have even seen that snakes from the same family and even the underlying subfamily have different venom composition. And that is because they adapt to the environment in which they operate.”

In addition to the scientific side, Haselberg wants to discuss this during his lecture online Life Science event pay attention to the acute problem of snakebites: “Many people die from this every year because there are no good medicines. And too little research is done into snake venom, because it is not always a high priority. We now also hope that by knowing what different types of poison look like, we can also make better anti-venom. But it remains long-term research. I also hope to be able to measure even more sensitively, so that we know even better in depth what a poison consists of. And we may one day be able to arrive at a universal antidote.”