Mass spectrometry for proteomics - part 2

[calistalawver]

Helping a ton for my proteomics course final! Thanks!!

[langli]

It's too wonderful and helpful. It's the time when I need. Thank you so much.

[NanogSo]

Very easy to follow along and clear overall material presented in the video. Thank you very much, it is a pleasure to learn with you explaining these novel to me concepts.

[lethanhtoan]

You are such a life-saver! I am doing the final thesis for my master course and I am having the worst tutor/mentor ever. It is too late and too risky for me to change the mentor now. Your videos really help me a lot.
Hope that in a year, I can have everything sorted out.

[suinberlin]

Hello Matthew,
amazing video!!! Thank you for sharing

[manikantakolasani]

love u mathew i wish u keep posting the stuff

[sophierafalimanana]

Thank you, i understand very very well! You save me before my exam

[sarantis]

your explanatory videos are ultra helpful! I am a masters student in biochemistry lab and these now form the basis of my understanding of MS. I have a question however:
Why do we subtract another 18 amu (a H2O molecule) from the intact peptide in addition to the largest b ion in order to determine the first (and why only the first?) aa from the carboxyl-terminal (lys/arg), as in:
intact – b3 – 18 = lys/arg ?
instead of: intact + 18 = b3 + lys/arg => intact + 18 – b3 = lys/arg ?
Aren't we referring to the water molecule that breaks the peptide bond between b3 and lys/arg or am I missing something ?

[TanTan-chvq]

At 3:42, you said “ in electrospray, protein an d peptide having multiple (what?) can be protonated, ”, thanx

[shawnwang]

Anyone notice how part 2 came out a year before part 1

[abhiramips]

at 7:00, you say that the difference between 1337.5 and 1276.5 is lesser than 57, hence its not a y ion and therefore a b ion. But, the difference between them is actually 61. Hence the reason why you took it as a b ion is because there is no amino acid with a weight of 61 right?

[BabayBunny]

I wonder how you know if you need to subtract a water molecule or not from the fragment.

[moizzaarshed]

I have a question. How can you differentiate leucine from isoleucine using this mass spectrum?

[rogertruscott]

Specta is plural. One is a mass spectrum.

[harisredy]

Hi Matthew, If the spectra is from a doubly charged mass precursor, do we look for the masses below the precursor mass or true mass of the precursor? If the precursor was 650 (doubly charged) - should i look for masses below 650 Da or nominal mass of 1300 Da?

[MrAbemis]

Hi, where can I find the original figure you use at 3:02?

[shwethaumesh]

Thank you for the explanation Matthew.
Could someone recommend a good online course for proteomics?
Thank you :)

[ForKSapien]

Thank you for this amazing tutorial. Do you know what software I can use to determine the sequence of MS2 as explained around 7:00?

[tamkinaslanli]

What do you mean by Quadrupole one in the isolation step in 2:37?

[UsmanTariq]

Correction: Phenylalanine is 147. The largest mass amino acid is Tryptophan with the mass of 186.