You are the best chemistry teacher I have experiences in my entire life. You explained in 10 minutes what a teacher from my university with mlre than 20 years of experience could not explain in one hour clearly. Hands down my friend hands down indeed.
Thank you so much for sharing these very thorough lectures! Very glad I came across these - so concise and well thought out, I can more fully appreciate how our bodies operate! You have quite a gift for teaching!
I'm from algeria and I'll pass my Bac in 1 week , I've been chearchig for the analysis of this experiment and the meaning of the result of each steps of it , I'm not even fluent in english and I understood everything OMG THANK YOU SO MUCH .
I'm a French student and listening to your videos helps me a lot to understand !! you explain very well and you speak Also very well which helps me to understand. Thanks a lot !! You save my test
In experiment 3. The resulting solution was similar to that of experiment 2 where urea was still present. How then was the activity or protein structure fully recovered since urea breaks down hydrogen bonds?
OK, so....... This is my summary, if I am wrong about something, please correct me. Christian Anfinsen used RNAase A (an enzyme that breaks down RNA, it's structure has 4 disulfide bridges between 8 pairs of cysteine sidechains), UREA (A polar substance that can disrupt the Hydrogen bonding of the 3 dimensional enzyme) and Beta Mecraptoethanol (a reducing agent that is capable of breaking disulfide bridges between a a pair Cysteine Side chains). Of course, he calculated the normal enzyme activity before starting the experiment. Trial #1 He placed RNAase A sample in Urea, which denatured the enzyme by changing it's tertiary structure, as a result the active site shape is altered, so it no longer fitted the substrate (RNA). Enzyme activity was 0% in Urea. Urea was removed through dialysis, the enzyme activity was brought back to 100%. TRIAL #2 He placed RNAase A in a High concentration of BETA Mecroptoethanol, this also caused enzyme to denature, and now it no longer fits the substrate and activity was 0%. Upon removal of the reducing agent, disulfide bridges were "rebuilt" (because the normal environment is oxidizing), which brought enzyme activity back to 100%. TRIAL #3 It started like TRIAL #2, but this time, Urea was present so when the Beta Mecroptoethanol was removed, disulfide bridges formed between the wrong pairs of cysteine side chain. Even after Urea was removed, the enzyme activity was back to only 1%, so the wrong structure was maintained, except for a minuscule number of enzyme, which Afinsen Hypothesized was due to the random nature of protein folding TRIAL#4 He added a small concentration of Beta mecraptoethanol to the solution in TRIAL #3, with the Urea removed. This allows disulfide bridges to break and reform in the same mixture. The old structure was not restored in a matter of seconds, in fact, it took 10 hours for the enzyme activity to reach 90% it's normal activity. Conclusion Urea shifts equilibrium the folded state, to the unfolded state of RNAase A. Disulfide bridges help reinforce the structure of the enzyme. Don't smoke weed.
So the native ribonuclease reformed because it is thermodynamicly stable got that. But how does the beta-mercoptoethanol not just keep breaking the disulfide bonds after they formed? Is it used up or something?
Wrong way to folding can change nothing . I have solved the problem, but unfortunately I have met a conceited Science editor. She know nothing about refolding. The key is "freezing".
You are the best chemistry teacher I have experiences in my entire life. You explained in 10 minutes what a teacher from my university with mlre than 20 years of experience could not explain in one hour clearly. Hands down my friend hands down indeed.
CHIRRIN GARCIA thanks! appreciate that :)
all your videos are some of the best explanations ever! please continue making these, thankyou!.
Great Lecture , You help me more than my teacher.
This lecture is amazing and SO EASY to understand. Thank you so much!
Thank you so much for sharing these very thorough lectures! Very glad I came across these - so concise and well thought out, I can more fully appreciate how our bodies operate! You have quite a gift for teaching!
I couldn't find information about this experiment through other webpages but by listening your lectrue i could solve what i wanted. Thank you so much.
I'm from algeria and I'll pass my Bac in 1 week , I've been chearchig for the analysis of this experiment and the meaning of the result of each steps of it , I'm not even fluent in english and I understood everything OMG THANK YOU SO MUCH .
This was extremely helpful. Thank you so much for the clarity of the content as well as the explanation.
Well broken down and those graphics really helped me visualise and understand better! THANKYOU ^^
I'm a French student and listening to your videos helps me a lot to understand !! you explain very well and you speak Also very well which helps me to understand. Thanks a lot !! You save my test
Thank you sooo much! I finally understood everything. You're the best!
Greetings from Serbia :)
So clear and so helpful, even for strangers, thank you !
Fantastically explained which made me to understand the concept very well.....Thanks buddy...!!
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Thanks for making it comprehensive
This was amazing. God bless you.
Very well explained, you really saved me a lot of time, thank you so much.
This video was very clear to understand the protein folding. Thank you so much.
Very clear and helpful explanation. Thank you!!
In experiment 3. The resulting solution was similar to that of experiment 2 where urea was still present.
How then was the activity or protein structure fully recovered since urea breaks down hydrogen bonds?
Thanks. Extremely good explanation. Nice teaching 👍
This is great, thank you so much! The textbook was so confusing on this topic. I'm definitely subscribing.
Thanks Alex, glad to hear it! :)
Brilliant Summary!
You explained it really well. Thank you!
Thank you for the explanation!
OK, so....... This is my summary, if I am wrong about something, please correct me.
Christian Anfinsen used RNAase A (an enzyme that breaks down RNA, it's structure has 4 disulfide bridges between 8 pairs of cysteine sidechains), UREA (A polar substance that can disrupt the Hydrogen bonding of the 3 dimensional enzyme) and Beta Mecraptoethanol (a reducing agent that is capable of breaking disulfide bridges between a a pair Cysteine Side chains). Of course, he calculated the normal enzyme activity before starting the experiment.
Trial #1
He placed RNAase A sample in Urea, which denatured the enzyme by changing it's tertiary structure, as a result the active site shape is altered, so it no longer fitted the substrate (RNA). Enzyme activity was 0% in Urea. Urea was removed through dialysis, the enzyme activity was brought back to 100%.
TRIAL #2
He placed RNAase A in a High concentration of BETA Mecroptoethanol, this also caused enzyme to denature, and now it no longer fits the substrate and activity was 0%. Upon removal of the reducing agent, disulfide bridges were "rebuilt" (because the normal environment is oxidizing), which brought enzyme activity back to 100%.
TRIAL #3
It started like TRIAL #2, but this time, Urea was present so when the Beta Mecroptoethanol was removed, disulfide bridges formed between the wrong pairs of cysteine side chain. Even after Urea was removed, the enzyme activity was back to only 1%, so the wrong structure was maintained, except for a minuscule number of enzyme, which Afinsen Hypothesized was due to the random nature of protein folding
TRIAL#4
He added a small concentration of Beta mecraptoethanol to the solution in TRIAL #3, with the Urea removed. This allows disulfide bridges to break and reform in the same mixture. The old structure was not restored in a matter of seconds, in fact, it took 10 hours for the enzyme activity to reach 90% it's normal activity.
Conclusion
Urea shifts equilibrium the folded state, to the unfolded state of RNAase A.
Disulfide bridges help reinforce the structure of the enzyme.
Don't smoke weed.
thank you AK LECTURE
Thank you so much! Better than my textbook.
beautiful explanation
Thank you so much! B-) it was a little difficult to understand by just reading the journal, you've explained it really well.
God bless you for this ...
Best explanation to exist
U have made biochem soo easy..thank u
Well explained thank you ❤🎉
Andrey does it again
omg this really came in clutch for my bio midterm in 3 hrs lmao
Great explanation 🙌🏾
incredible thank you so much!!!!!!
It took me watching this video to realize my teacher explained this completely incorrectly to 500 kids. Thank you!!
Thank you for the explanation it was very helpful
Thank you
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AK you are excellent lecturer
Thank you!
Awesome!! Thanks so much. I was was confused before but now I get it. :)
very good explanation.
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Thank you so much
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¡Un maestro!!
Even when english is not my first language!!!
Thank you!
Wiem Abidi you're welcome ! :)
This was amazing thank you!!!!!!!
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Amazing!
Hello Mr AK,
Could you please make a video on prions and misfolding
Great.
Could you make one about CRISPR?
Regards and Congratulations from Argentina!
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Thanku sir
Legend
Danke ! Thanks
sirrrrrr..... this is lit.. im clear asf now rather in lecture hall
great .... thanks :)
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Thanks my broder. I must read the papper but this video is awesome!
PD: Regards to Gatitos de la iglesia 😺
Sir,How will you say ..that disulfide bond made only between cystine..why not methionine??
exelent!
So the native ribonuclease reformed because it is thermodynamicly stable got that. But how does the beta-mercoptoethanol not just keep breaking the disulfide bonds after they formed? Is it used up or something?
You should be the one I pay the tuition to.
Explation is good sir but write some big letters because I will note the points
HELP!
why ,when proteins are denatured and renatured, they only regain part if their original activity....
In experiment 2, how to remove 2-ME only but not simultaneously remove urea?
Nyc
Wrong way to folding can change nothing . I have solved the problem, but unfortunately I have met a conceited Science editor. She know nothing about refolding. The key is "freezing".
I dunno man , i'm going to think that Basically i've understood it all and Basically want to thank you
that is nirvana, anything can be better than this
thanks sir,,,,but please marathi in translation
beautiful explanation
Thank you !
Thank you!