#membrane proteins

[cbirt]

It is still very difficult to construct complex protein folds from scratch using only computational methods. École Polytechnique Fédérale de Lausanne (EPFL) scientists create intricate folds and soluble counterparts of essential membrane proteins using a powerful deep-learning pipeline. Researchers show that the structural characteristics of unique membrane topologies, including those from G-protein-coupled receptors, may be reproduced in solution. These topologies are not present in the soluble proteome. Designing complex protein topologies with functionality derived from membrane proteins has yielded high experimental success rates. These designs show excellent thermal stability and extraordinary design precision, which may open up new avenues for drug development. The functional soluble fold space was shown to have the ability to expand when the soluble counterparts were functionalized with native structural motifs.

A key step in developing artificial proteins with novel functions is protein design, which broadens the scope of nature’s molecular apparatus. Historically, physics-based methods such as Rosetta have been employed; however, they necessitate a great deal of experimental screening and optimization, which makes the creation of functional proteins with intricate structural topologies challenging.

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[er-cryptid]

Intrinsic Membrane Proteins

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[scenic-route33]

Being a biology student and also being obsessed with red valley makes it really fun when your lecturer even fucking mentions the prefix cryo

[biologist4ever]

Lipid rafts are specialized microdomains within the plasma membrane, rich in cholesterol and sphingolipids, that play a critical role in organizing cellular processes. These dynamic structures act as platforms for signaling molecules, facilitating key functions such as immune responses, cell communication, and membrane trafficking. 

Recent research has revealed the importance of lipid rafts in various diseases, including cancer, neurodegenerative disorders, and viral infections. Understanding how lipid rafts organize and modulate cellular activities opens up new possibilities for targeted therapies that could disrupt or harness these microdomains to treat diseases more effectively. As studies on lipid rafts advance, they are proving to be essential components of the plasma membrane's complex architecture and function.

[miss-biophys]

New publication out!

We were curious what happens with the lipid membrane if proteins are inside. As a model of membrane proteins we use transmembrane peptides with neutral and positive charge. The charges turn out to be quite crucial in the peptides influence on the lipids.

publication link: https://doi.org/10.1016/j.colsurfb.2024.113765…

All transmembrane peptides hinder mobility of lipids around. The positive charges in the peptide make this hindering a long range influence.

The membrane with the positive peptides then has heterogeneities in the lipid mobility. This hampers free rearrangement of lipids and leads to lower ability to seal ruptures. You can see below how the membrane stays fragmented after indentations with AFM (atomic force microscope), which is basically a very tiny tip that scans the surface of the membrane for images and can also push through it to test mechanical stability.

For comparison this is how it looks like with a membrane without any peptides. The mebrane seals the ruptures induced by the AFM tip and recovers its round shape. The same happens if we have a neutral, non-charged, peptide.

With this work we highlight the importance of including charges of proteins and peptides in membrane model studies.

And last but not least...

This is the very first time I am the last corresponding author of a publication. I am immensely proud on myself!

[jalbert-james]

the cell membrane is just a little gatekeeper who says “answer my riddles three, and i’ll give passage to thee!” and sometimes you get the riddle right. but other times you get your buddy Protein to kick his ass for you

[bubble-you]

read a post about if the doctor was a vampire and got snacks from friends. just a bite. and uhh a little horrified because proportionately they’d probably need like 1L of blood at LEAST to be full. And that’s like 25~30% already. So say a snack. But Rory would apparently draw blood for 11 using a needle, and that’s alright, that’s only 5 ml or 10 ml, at most 20. That’s a reasonable snack, if you were to give that away.

It doesn’t dull the dread of if they were to really drink. That’s your strength. Also… the puncture wound needs to heal. Bruises. Anemia. Drained. Unstoppered.

[darksouls2yuri]

Hi, is there anything you like about Dark Souls 2 in particular? I have the game and I somewhat want to play it? But I haven't heard many positive things in particular, and it's leaving me sorta discouraged. I'm just really unsure if I'm gonna like it. 😅

so upfront anon, you'll never know if you like it if you dont play it!!! be free have fun and try it since you already have it. with that being said;

AAAAA ANON DO YOU HAVE DS2 OR DS2 SCHOLAR OF THE FIRST SIN? I have both. sotfs on ps4 and vanilla on pc, I like vanilla ds2 worlds worlds better than sotfs. So in my opinion which version you have determines enjoyability, but just my opinion. I really dislike sotfs for the changes it made to the game. (see this ask) also upfront if you've already played dark souls dark souls 2 is not going to be the same experience. dark souls 2 is pretty much a different beast gameplay and storywise <- obviously there are lots of tie ins with dark souls but ds2 is set in a different place in arguably almost like its own bubble in time as well. which well is something i like. i really enjoy how different it is from dark souls as well as dark souls 3

As far as what I enjoy about ds2, I love the atmosphere, it is in my opinion the best looking souls game. It has the best environments and design choices. The soundtrack is amazing as well. Something I know others dislike is the amount of bosses (ds2 is like what, double the length of either ds or ds3??) & types of bosses there are. Im a big fan of the optional bosses. I also am insane and love the gank fights between multiple bosses, Ruin Sentinels is my favorite boss!!!! Its just super awesome and theyre so fun to fight. dark souls 2 does have an issue with crush being like. the main damage type a shit ton of bosses are weak to, but tbh i dont find it that annoying except for stupid bitches like smelter demon (just bring lucatiel or a buddy with you for it. smelter demon sucks 😑) i actually really like the combat feel. i really disagree with the sentiment i see where people say you have to fill out the paperwork to attack; my experience playing dark souls has been like that. ds2 has been really responsive and feels good to play. also ds2 for pc is very well optimized i can play it on my shitty laptop from 2010 whereas dark souls stutters on my pc from 2019.

i really really like ds2 and i would really suggest trying it!! its okay if its not for you also, be free have fun forever. i will say ds2 is also much easier than the other two for a few different reasons (first that comes to mind is the amount of healing options you get. on my main save i have an insane surplus of life gems) so if you feel like itll be hard dont worry i can play it and well. im definitely not a gamer im literally about to go play peggle after i finish this ask.

if you do play try out hexes!!!! hexes are awesome and bc of their stat requirements you can use sorceries and some miracles too. also the choice to level adp is yours and yours alone. i really genuinely dont see a difference in iframes personally eventhough i know functionally it does increase them. attunement also increases your agility alongside adp so if youre going for a caster then. yknow 😃

[evvywevvy]

check out this article about biomolecular condensates!

you might know that your cells contain organelles, little specialized sub-parts like nucleus, mitochondria, and ribosome, all suspended in a fluid called cytoplasm. it turns out that there are some globby bits of RNA and ugly proteins also floating around and doing important cell stuff we didn't even know about until the last couple decades!

not only are these biomolecular condensates present in eukaryotic cells (animals, plants, and fungi) where they were discovered, but also in prokaryotes (e.g. bacteria), which *don't* have organelles! this helps explain what's going on inside prokaryotic cells.

BUT ALSO this is kind of a missing link in evolutionary biology: we know how RNA and simple proteins can form from simple and abundant chemicals, but we didn't know how to get lipids, which are needed to make the membrane that comprises the outside of a cell or organelle. now we know that you can have an organelle without a membrane. that means there is a plausible and complete path from chemicals to RNA to proteins to biomolecular condensates to organelles to clusters of organelles to single cells to capturing other cells and eventually reproducing as a whole, to multicellular entities, to plants and animals and fungi!

biology was the science of least interest to me in high school, but since I've started learning more about evolutionary biology, I'm absolutely blown away by how cool everything is all the time

[medicomunicare]

Cholesterol in brain network: how does its presence affects health or neurodegeneration?

Cholesterol in brain health and disease Cholesterol is found in the cell membranes of all human cells. It plays an integral role in neuronal signaling and synaptic connections, especially in the brain. Notably, the brain contains between 20-25% of all the body’s cholesterol reserves, making it the organ with the highest cholesterol concentration in the human body. Interestingly, peripheral…

[smoothpeanut]

reminiscing about how i ended up in an online biology class way above the level i should have been in. the professor would show us his mug of tea and tell us what tea he was drinking. and said we should take a break and drink some tea as well. 90% of the lecture im like my guy, i have no fucking idea what you're talking about. then oh wait teatime yay :)

[cbirt]

Can you imagine that you can design proteins that have a particular function, and they are like small robots working inside our cells? This may be the reality pretty soon. Researchers from the University of California and Yale University came up with an innovative way of creating transmembrane proteins from scratch, thus leading to targeted treatment and a better understanding of cell biology. However, before we dive into this thrilling research, let us first look at what proteins and membranes are.

Picture your cells as something like busy factories. Proteins make sure these little factories keep running smoothly the entire time. They exist in a multitude of forms and sizes, each having its own work. Some function as enzymes, which are catalysts for chemical reactions, while others transport molecules across membranes, which enclose every cell as protective barriers.

There is a special kind of protein called Transmembrane proteins; it has a unique structure. It has got a hydrophobic section embedded within the cellular membrane, just like the screw goes into a cork bottle stopper. This part is known as transmembrane domain (TM domain). Depending on its purpose, the other part of the protein can stay in or outside the cell. These domains act as channels for molecule exchange between cells.

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[whats-in-a-sentence]

As shown in Figure 24.12, responses to temperature stress, oxidative stress, salinity and osmotic stress, and drought stress are all regulated by modules of the same basic MAPK pathway.

"Plant Physiology and Development" int'l 6e - Taiz, L., Zeiger, E., Møller, I.M., Murphy, A.

[tenth-sentence]

High concentrations of salt cause protein denaturation and membrane destabilization by reducing the hydration of these macromolecules.

"Plant Physiology and Development" int'l 6e - Taiz, L., Zeiger, E., Møller, I.M., Murphy, A.

[miss-biophys]

My very first paper as the last corresponding author was just accepted today!

Coincidentally, today is also exatly 5 years since I sent my PhD thesis to print before the defence.

[hidden-but]

an advantage of calculating mass density compared to calculating hydrogen bonds is that

I

CAN

OMIT

HYDROGENS