Today I finished banging out a new Wikipedia article – for a scientist who’s really cool – thanks to her we better understand how muscles pull! Ilona Banga was a Hungarian biochemist who codiscovered actomyosin – the actin/myosin combo that makes muscles contract so you can act! And how it happened is a pretty cool story. But first a bit about Ilona – because she deserves more people knowing about her – which is why I created that Wikipedia article which I hope you’ll check out (and improve!) to learn more about her.
video added 7/3/22
Ilona was born in Hungary in 1906. After getting a master’s degree in chemistry from the University of Debrecen, she joined the lab of Albert Szent-Györgyi at the University of Szeged as a research assistant. It was in his lab that she carried out the muscle stuff I will get into below. But before she did that she contributed to the work that would earn him the Nobel Prize in 1937.
The prize was for work they did on metabolism and vitamin C. And to do that work they needed a lot of it. So she developed methods for purifying large amounts of ascorbic acid (vitamin C) from Hungarian paprika – and a ton of it – literally (at least almost literally) – the protocol involves 450 liters of paprika pulp! All that gave her 3kg of the stuff – which you can now buy online for less than $60.
After winning the Prize, a new research topic caught Szent-György’s eyes – muscle movement. Another couple of scientists, Militza Ljubimova and her husband Vladimir Engelhardt, had found that the major muscle protein myosin wasn’t just a structural protein – it could do stuff – specifically, it had ATPase activity – it could split ATP to form ADP and a free Pi. Banga confirmed their findings and then did more work on mysosin. And to do those experiments she needed myosin – paprika wouldn’t do it this time. Instead she turned to rabbit muscle tissue. She carried out experiments in which she minced rabbit muscles, stuck that in saline (salt water) and after giving it some time (originally 20 min), she’d spin it down really fast (centrifuge it) to pellet out all the insoluble stuff. And the myosin would be left in a thin liquid layer.
One time she ran out of time to do the extraction (there was a cool talk to go to) so she left the minced muscle sitting in saline overnight and when she came back the next morning instead of the usual thin liquid appearance of what they called the “20 min myosin” they saw a thick, viscous goop – and when they analyzed it they found that it was myosin – so they called it “24 h myosin” – “24h“ vs “20min” is a bit of a mouthful, so they named them myosin A and myosin B.
Curious as to what could be going on, they added ATP to it – and, curiously, they found that it turned thin again (the Michael Finnigan song popped into my head when I wrote that)
There was a cool thing called myosin—B-agin
It lived in a liquid that was thin-so-thin
Left to sit it’ll turn to gelatin
But add ATP & it’ll get thin again!
(then after a while it’ll turn to gelatin again!)
The project was then given to another associate, Bruno Straub, to figure out what was causing this – and Straub found that the “24h mysosin” (myosin B) was really a mix of the “20min myosin” (myosin A) and another protein they named actin because it was “activating” the myosin to thin out when ATP was added. They called the combined myosin A/actin thing “actomyosin.”
Straub figured this out by selectively denaturing (unfolding) the myosin by treating muscle with an organic solvent – he could then “dry out” the muscle (dehydrate it) and then “get it wet” – when he added water he could dissolve the actin & leave behind the messed-up myosin that’s denatured and clumpy and doesn’t want to dissolve. This gave him pure actin. And if he added that to the “20 min myosin” (myosin A) it turned into that “24h myosin” (myosin B).
With the ability to purify actin & myosin & mix and match them thanks to Struab, Banga did some seriously thorough biochemical characterization of the proteins involved – it turns out there are scientific ways to measure “goopiness” – so she performed experiments to measure viscosity under different conditions.
And their lab also measured “myosin activation” in another pretty cool way – they found they could take threads of actinomyosin and add ATP & it contracted – this was the first time a protein system taken from muscle was shown to respond to ATP with mechanical changes. The experiments they were inspired by showed that myosin used ATP (and Banga did a lot of work characterizing how) but before this, ATP spending hadn’t been shown to be directly linked to actual contraction of things in a tube as opposed to in intact muscle tissue.
We now now, in large part thanks to work by Banga & colleagues, that myosin and actin work together in muscles in a “sliding filaments” mechanism (this mechanism was proposed by Huxley) – myosin forms long strands and actin forms strands when it polymerizes (a bunch of the globular form, actin-G, link up to form the filamentous form, actin-F). And those strands interact kinda like
They contract because the myosin strands have heads that bind & unbind the actin strands to pull them closer together
And the unbinding requires ATP. So when they added ATP to that “24 h myosin” they caused the myosin to let go of the actin that was keeping it all together, so the liquid thinned out. But then the myosin split the ATP into ADP + Pi – and the ADP-bound form can bind the actin – so the myosin latched on again and the liquid gooped up again.
When Banga did the myosin extraction with fresh muscle (the 20 min myosin), where there was plenty of free ATP, the myosin bound that ARP, so it “unbound” the actin. Under the high salt conditions they used, the myosin-ATP was soluble, but the actin wasn’t, so the actin got pelleted out, but the myosin stayed floaty (remained in the supernatant). But when she extracted myosin from the muscle that had soaked overnight, the myosin was bound to the actin because it had spent up all the free ATP so it couldn’t “unbind”
Something that makes Banga and her co-workers’ discoveries all the more remarkable were that they were being carried out in occupied Hungary during WWII. Szent-Györgyi had to go into hiding because he was wanted because of his anti-Nazi activities. This left Banga to protect the lab and all of its valuable research equipment – and that was no small task. Towards the end of the war, German troops were leaving, Soviet troops were arriving, and Hungarian thieves were always present. So she posted notes (written in German, Russian, and Hungarian) on the door of the Institute of Chemistry saying it was researching infectious things and providing sample drop-off hours for infectious materials. This scared away anyone who wanted to take their equipment and the Institute for Medicinal Chemistry remained intact – it was the only institute at the university to not have its facilities or equipment damaged.
When Szent-György left Hungary for the US after the war, Banga stayed. And took a new position – chief of the Chemical Laboratory of the First Institute of Pathological Anatomy in Budapest; and a new research partner – the pathologist József Baló, whom she married and worked closely with until his death in 1979. Much of their work focused on changes that occur to your veins when you age. They were interested in figuring out what causes degradation of the elastin fibers holding together the walls of veins – and their searching efforts proved not to be in vain! They found an enzyme made by the pancreas that could do it – so they named it elastase. Turns out there are actually more elastases and this one probably doesn’t play a role in arteriosclerosis but it was the first one discovered – and Banga and Balo did it! Fellow scientists were skeptical but Banga was able to crystallize elastase (and her conclusion)!
Banga banged out a lot of papers – in addition to the 25 or so she wrote in Szent-György’s lab, she published more than 60 more just in the years from 1948-1965. She retired in 1970, but aging wouldn’t keep her from engaging with scientists studying aging! She served as a scientific advisor for the Gerontology Institute from 1971 to 1986.
She was the first female associate professor at the university, but she was never promoted to full professor. But she did win some pretty prestigious awards – including the Kassuth Prize and the 1st Szent-György Prize. You can learn more about Banga on her Wikipedia page! https://en.wikipedia.org/wiki/Ilona_Banga
And you can improve it – and/or create pages of your own. Because ANYONE can edit Wikipedia. I got inspired by Jess Wade. I saw her work on Twitter & got inspired so I started creating, expanding, & improving Wikipedia articles on #womeninscience and other things.
#WomenInSTEM “Wiki-Warriors” like Wade don’t have to go it alone! You, yes YOU can help! You don’t have to create whole new articles (tho you certainly can!). Many female scientists have articles that are just “stubs” (few sentences) or way too short for what they deserve. Others have articles that are OK, but need copy editing. Every bit helps!
link to the Banga paper: http://actin.aok.pte.hu/archives/pdf/StudiesI_1.pdf
more on Wikipedia editing: http://bit.ly/wikieditingintro