Well presented ! I believe active methylated forms of B6 - P5P, folate - 5MTHF, B12 - methylcobalamin along with free form Glycine and Methionine are critical for driving folate, methionine & transulfuration pathways. Note : Serine can be derived from Glycine and vice-versa in the 1C metabolism. Methionine is a critical precursor for biologically vital molecules SAMe, cysteine, taurine, and GSH. Methionine compounds with zinc & selenium are also clinically relevant. Methionine is also a precursor for synthesis of creatine, and carnitine. SAMe is super critical for methylation of DNA, proteins, neurotransmitters, NE, PC, SR, and for supporting methyltransferases. Cysteine is critical for GSH (rate limiting) along with Glycine. Cysteine zinc proteins are vital and used for transcription, while cysteine seleno proteins are used in detox pathways. However, Cystine (not cysteine) can spur reactive nitrogen & oxygen species. Taurine is vital not only for bile salt synthesis (along with Glycine), it is critical for redox balance - its an antioxidant. Note the cysteine metabolism can also generate sulfites which are toxic if not conveted to sulfates. This process requires molybdenum and sulfite accumulation is common is people with MoCo - molybdenum cofactor deficiency. Note2 : Having NAC is NOT equivalent to upregulating intracellular GSH bcoz GSH synthesis requires several cofactors including methionine/cysteine, glycine, glutamate, selenium, magnesium, B6, B2, B3, heme (glycine), vit C (redox cycling). It also is dependent of GCLC gene and many folks have mutation of GCLC.
Cysteinuria - defective transport of cysteine along with ornithine lysines and arginine While in cystinosis -cystine reductase deficient lead to accumulation of "cystine"
Correction: In Cystinosis, there is intracellular accumulation of CYSTINE, NOT CYSTEINE, generally due to deficiency of cystine reductase. Two molecules of cysteine condense via disulfide linkage to form the dimer Cystine. Cystinosis is about abnormal accumulation of Cystine, not Cysteine esp in lysosomes.
Correction: Cystinuria is an inherited autosomal recessive disease[1] characterized by high concentrations of the amino acid cystine (NOT cysteine), in the urine, leading to the formation of cystine stones in the kidneys, ureters, and bladder. It is a type of aminoaciduria. "Cystine", not "cysteine," is implicated in this disease; the former is a dimer of the latter.
Tq tq tq so much Sir u r doing good job Sir because i fell biochemistry subject is very Hard but when i started to see ur video it make me very easssy Sir tq Sir number of students r waiting for ur viodes Sir we r blessed Sir
Causes of Homocystinuria and implications: 1. Slow CBS or CBS enzyme deficiency or CBS genetic mutations - can slow down degradation of homocysteine (via the transulfuration pathway), characterized by elevated serum homocysteine and depressed serum cysteine. Note: CBS enzyme activity is dependent on PLP (biologically active B6), serine/glycine availability, heme synthesis - CBS is a heme containing enzyme and excess or deficiency in heme can affect CBS activity, CBS heme Redox state - The heme cofactor in CBS acts as a redox sensor, regulating the enzyme's activity in response to changes in redox potential, The redox state of the heme is pH dependent. E.g The Fe2+ form of the enzyme is inhibited by binding CO or nitric oxide. Importantly - The enzyme activity is doubled when the Fe2+ is oxidized to Fe3+. 2. MTR/MTRR genetic mutations - MTR provides instructions to encode the Methionine synthase enzyme, so MTR/MTRR genetic variants can slow down methionine synthase activity which is responsible for remethylating homocysteine to Methionine, charterized by elevated serum homocysteine and depressed serum Methionine (in absence of sufficient dietery Methionine). 3. Cobalamin deficiency and Folate trap : Methionine synthase activity is dependent on Cobalamin availability, in absence of Cobalamin , 5MTHF is unable to transmethylate homocysteine to Methionine , unable to generate THF and methylcobalamin, and unable to facilitate transfer of methyl groups to homocysteine for conversion to Methionine - leading to elevation of homocysteine and the depressed Methionine levels also slow down biosynthesis of SAMe and all SAMe dependent transmethylation reactions ! Note: Sufficient availability of 5MTHF is also a required cofactor for remethylation of homocysteine to Methionine via Methionine synthase. 4. Note : Once SAMe has donated its methyl group in any of the transmethylation reactions, it is converted to SAH. Now SAH blocks COMT (catechol o methyl transferases) - why? Bcoz SAH is a potent feedback inhibitor of all methyltransferase(s)....including MTR - methyltetrahydrofolate homocysteine methyltransferase......and requires SAHH to split it into adenosine and homocysteine. So SAHH enzyme activity also impacts homocysteine levels - SAH buildup is correlated with CKD - chronic kidney disease, as kidneys are the main site for maintaining circulating serum SAH levels, you need NAD+ to facilitate SAHH activity, reduce buildup of SAH and blockage of COMT. Note that SAH maintenance and SAHH activity is critical to maintain optimal SAMe/SAH plasma concentrations.
Hi. Are these 3 amino acids depend on sulfur ? I can’t eat sulfur foods and B6. I believe my cysteine levels are not in balance but I don’t understand how it all works. I can’t take mo-Zyme forte it cause pain. What reaction is happening there and can you share any links where I can learn more about this? I don’t understand the role of glutamine and glycine. Also the meaning of methionine to cysteine recycling and methionine biosynthesis. Thanks
There are only 9 essential amino acids - methionine, lysine, leucine, isoleucine, valine, threonine, phenylalanine, histidine and tryptophan. Homocysteine is an intermediate protein that is undesirable in higher levels in serum, usually should be between 6-10 micromoles per ltr. Higher homocysteine levels increase susceptibility to cardiovascular and stroke events.
My son has been diagnosed with this rare sulfur blood born problem. He is in hospital now but the doctors know nothing about it. They are trying to research and problem solve. Is there a doctor out there that has worked with this. My son has had TBI Please help
Methionine synthase is also called MTR - methyltetrahydrofolate homocysteine methyltransferase , as it facilitate the transfer of methyl group from 5MTHF to homocysteine via cobalamin.
8:48 you said here that the cysteine have a sulfur from methionine and the rest of the molecule is from the serine !what is the rest of the molecule you mean homoserine!!!
I had zero hopes of passing my terms but now I am feeling like I can pass, after watching your videos
Best luck dear, be confident
@@Rajesh_Jambhulkar thank you so much sir🙏🙏🙏
All of my friends including me watch your videos for Biochem Sir❤️ Thanks for all your effort in doing this. These classes mean alot to us.
Well presented !
I believe active methylated forms of B6 - P5P, folate - 5MTHF, B12 - methylcobalamin along with free form Glycine and Methionine are critical for driving folate, methionine & transulfuration pathways.
Note : Serine can be derived from Glycine and vice-versa in the 1C metabolism.
Methionine is a critical precursor for biologically vital molecules SAMe, cysteine, taurine, and GSH.
Methionine compounds with zinc & selenium are also clinically relevant.
Methionine is also a precursor for synthesis of creatine, and carnitine.
SAMe is super critical for methylation of DNA, proteins, neurotransmitters, NE, PC, SR, and for supporting methyltransferases.
Cysteine is critical for GSH (rate limiting) along with Glycine.
Cysteine zinc proteins are vital and used for transcription, while cysteine seleno proteins are used in detox pathways.
However, Cystine (not cysteine) can spur reactive nitrogen & oxygen species.
Taurine is vital not only for bile salt synthesis (along with Glycine), it is critical for redox balance - its an antioxidant. Note the cysteine metabolism can also generate sulfites which are toxic if not conveted to sulfates. This process requires molybdenum and sulfite accumulation is common is people with MoCo - molybdenum cofactor deficiency.
Note2 : Having NAC is NOT equivalent to upregulating intracellular GSH bcoz GSH synthesis requires several cofactors including methionine/cysteine, glycine, glutamate, selenium, magnesium, B6, B2, B3, heme (glycine), vit C (redox cycling). It also is dependent of GCLC gene and many folks have mutation of GCLC.
Sir you are amazing..u are making this subject soo easy to study
Cysteinuria - defective transport of cysteine along with ornithine lysines and arginine
While in cystinosis -cystine reductase deficient lead to accumulation of "cystine"
These classes are best understanding the topic as well as for scoring marks
🙏 Thank u sir
TRUE
2 hours before exam 😗🫠
Update : class was literally superb.
As I studied in the last moment, could not recall what I lernt failed the internals 🫠🥲
A very good morning Doctor
I can't get enough of your chanel
Keep up the good work
7:50 sir textbook says Cysteine and à ketobutyrate are formed instead of homoserine.
Plz clarify
Same doubt
@@60.praveenkumarp25 can you suggest a text book for this topic please
@@applestone5812 vasudevan
cysteine and homoserine are formed and from homoserine u get a-ketobutyrate then propionyl then succinyl then glucose
Thnku alot sir,for ur great support,iam totally impressed with uu..all video of biochem i reffered from u😌😌😌
That was so clear and concise sir, Thankyou
Correction: In Cystinosis, there is intracellular accumulation of CYSTINE, NOT CYSTEINE, generally due to deficiency of cystine reductase. Two molecules of cysteine condense via disulfide linkage to form the dimer Cystine. Cystinosis is about abnormal accumulation of Cystine, not Cysteine esp in lysosomes.
Correction: Cystinuria is an inherited autosomal recessive disease[1] characterized by high concentrations of the amino acid cystine (NOT cysteine), in the urine, leading to the formation of cystine stones in the kidneys, ureters, and bladder. It is a type of aminoaciduria. "Cystine", not "cysteine," is implicated in this disease; the former is a dimer of the latter.
Tq tq tq so much Sir u r doing good job Sir because i fell biochemistry subject is very Hard but when i started to see ur video it make me very easssy Sir tq Sir number of students r waiting for ur viodes Sir we r blessed Sir
Causes of Homocystinuria and implications:
1. Slow CBS or CBS enzyme deficiency or CBS genetic mutations - can slow down degradation of homocysteine (via the transulfuration pathway), characterized by elevated serum homocysteine and depressed serum cysteine.
Note: CBS enzyme activity is dependent on PLP (biologically active B6), serine/glycine availability, heme synthesis - CBS is a heme containing enzyme and excess or deficiency in heme can affect CBS activity, CBS heme Redox state - The heme cofactor in CBS acts as a redox sensor, regulating the enzyme's activity in response to changes in redox potential, The redox state of the heme is pH dependent.
E.g The Fe2+ form of the enzyme is inhibited by binding CO or nitric oxide. Importantly - The enzyme activity is doubled when the Fe2+ is oxidized to Fe3+.
2. MTR/MTRR genetic mutations - MTR provides instructions to encode the Methionine synthase enzyme, so MTR/MTRR genetic variants can slow down methionine synthase activity which is responsible for remethylating homocysteine to Methionine, charterized by elevated serum homocysteine and depressed serum Methionine (in absence of sufficient dietery Methionine).
3. Cobalamin deficiency and Folate trap : Methionine synthase activity is dependent on Cobalamin availability, in absence of Cobalamin , 5MTHF is unable to transmethylate homocysteine to Methionine , unable to generate THF and methylcobalamin, and unable to facilitate transfer of methyl groups to homocysteine for conversion to Methionine - leading to elevation of homocysteine and the depressed Methionine levels also slow down biosynthesis of SAMe and all SAMe dependent transmethylation reactions !
Note: Sufficient availability of 5MTHF is also a required cofactor for remethylation of homocysteine to Methionine via Methionine synthase.
4. Note : Once SAMe has donated its methyl group in any of the transmethylation reactions, it is converted to SAH. Now SAH blocks COMT (catechol o methyl transferases) - why? Bcoz SAH is a potent feedback inhibitor of all methyltransferase(s)....including MTR - methyltetrahydrofolate homocysteine methyltransferase......and requires SAHH to split it into adenosine and homocysteine. So SAHH enzyme activity also impacts homocysteine levels - SAH buildup is correlated with CKD - chronic kidney disease, as kidneys are the main site for maintaining circulating serum SAH levels, you need NAD+ to facilitate SAHH activity, reduce buildup of SAH and blockage of COMT. Note that SAH maintenance and SAHH activity is critical to maintain optimal SAMe/SAH plasma concentrations.
This is great 👍 excellent job. 👏
Hi. Are these 3 amino acids depend on sulfur ? I can’t eat sulfur foods and B6. I believe my cysteine levels are not in balance but I don’t understand how it all works. I can’t take mo-Zyme forte it cause pain. What reaction is happening there and can you share any links where I can learn more about this? I don’t understand the role of glutamine and glycine. Also the meaning of methionine to cysteine recycling and methionine biosynthesis. Thanks
How selenium plays role in this process to glutathione?
Sir God bless you.... 😭❤️
Badhiyaaaaa!!!
Your video lectures solve all my doubts, thank you sir
Plasma homocysteine levels are inversely related to plasma levels of folate, B12, and B6???
To supplement Methionine, do we need to work on vitamin B’s first ?
amazing video sir
thank you sir for this great information
plz make video on branched chain amino acid plz
No one can replace you
How to calculate methionine cysteine ratio in poultry feed
Sir you did not mention about glutathione synthesis??
Our whole college is dependent on him 😂😂😂😂 #thesaviour
Sir cysteine dioxygenase likha hnn kyu middle ma
Sir upload glycine metabolism
Uploaded, thanks
Thanks sir .
Pls add subtitles for better experience 😀😀😀...
Great work sir 👍
Thank you sir 😊👌
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Thnx a lot sir
.✌🖤🌻
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Cystothianine gives cysteine and ketoglutaric acid
Sir i take supplements n acetyl cystein en trimethilglisin. You think is safe ? Or you dont recommend this
Which country you are from ?
@@debasmitde8801 why?
Amazing
Thank you so much sir.
Very useful videos sir
Thank you so much sir 🙏🙏❤❤
Thankyou so much sir❤️
Thanks sir
Thank u sir 🙏🏻💚💜
Sir Homocysteine is essential or non- essential amino acid??
There are only 9 essential amino acids - methionine, lysine, leucine, isoleucine, valine, threonine, phenylalanine, histidine and tryptophan.
Homocysteine is an intermediate protein that is undesirable in higher levels in serum, usually should be between 6-10 micromoles per ltr. Higher homocysteine levels increase susceptibility to cardiovascular and stroke events.
My son has been diagnosed with this rare sulfur blood born problem. He is in hospital now but the doctors know nothing about it. They are trying to research and problem solve. Is there a doctor out there that has worked with this. My son has had TBI Please help
Plz refer to higher centres for follow up and treatment. ( Mumbai, Delhi, Bangalore, chennai) or any metro City near to u.
Very nice explanation sir...tq so much sir
Sir instead of homoserine can we take Alpha ketobutyrate so that we can add metabolism of leucine and threonine?
Thank you sir 🔥🙏
Sir can you please discuss on aromatic amino acid metabolism..
Sir is methionine synthase and homocysteine transferase are same?
Methionine synthase is also called MTR - methyltetrahydrofolate homocysteine methyltransferase , as it facilitate the transfer of methyl group from 5MTHF to homocysteine via cobalamin.
U r ultimate sir🙏🙏🙏🙏🙏🙏
Thanks sir🙏
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Good morning sir
Sir structure be sath main banao na
Sir metabolic acidosis and alkalosis ka video banadijiye
Sure,
Will take time
tqq sir
Great Sir 👍👍
8:48 you said here that the cysteine have a sulfur from methionine and the rest of the molecule is from the serine !what is the rest of the molecule you mean homoserine!!!
the remaining molecular structure of cyteine i think
Tq u very much sir
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Thanks sir for best explanation
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Sir aap kon si book preferre kar to ho
DM Vasudevan for UG
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Sir , could you please provide pdf note for each topic 🙏
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oh
Replay plz.. sir
Thank you sir🙏😀
Thank you sir
Tqq soo much sir
Thank you sir
Thank u sir
Thank you sir