Will you provide your keen insight and communication skills to inform participants on this thread what the illustration illustrates. For example, what are b3, b4 etc... b
*shrug*. Okay, but I don't see what point there is in giving a mini-tutorial on how to read mass spectrometry charts... Did you miss that day in school or something?
I'm a little rusty, and too tired to look it up right now, so if I misremember some details, feel free to consult an appropriate text.
These are charts of the results of a tandem mass spectrometer analysis of two different proteins (one on the top, another on the bottom). The initial processing stage of the MS/MS analysis involves charging the protein molecules and subjecting them to collisions, which breaks them up into varying sized fragments, which are then in a sense "weighed and counted" by the spectrometer. The chart is the output of the proportional tallies of countless such molecular destruction-derbies.
The horizontal scale (X-axis) is the mass of the fragments detected (in daltons, IIRC), while the vertical scale (Y-axis) is the proportion of fragments which were of a given size.
The b1, b2, b3 etc. peaks are the different-sized ionized fragments that were captured -- "b1" is the fragments which consisted of one amino acid, "b2" is the fragments consisting of two amino acids, etc. Due to the nature of the preparation process, the "b" fragments all start at one specific end of the protein -- so the "b3" three-amino-acid fragments consist of the first-second-and-third amino acids in the protein, not the 4th-5th-6th, or whatever. And it's also possible to count the fragments starting from the other end, these are denoted as y1, y2, etc.
Given the relative size and positions of the peaks, it's straightforward to reconstruct the actual amino-acid composition and sequence of the original protein. These are the letters across the top of the chart -- every type of amino acid has a standard one-letter code, rather like the two-letter code standard abbreviations for the US states (TX = Texas, etc.)
So in short, this is the raw data by which the actual sequence structure of the two proteins was determined.
But really, tallhappy, you weren't all that interested in learning about spectrometer charts, were you? You were actually hoping that I wouldn't recognize those from one of the many papers I linked in post #185, so that you'd have a cheap and childish excuse to accuse me of not actually having read them, right? Grow up and stop playing immature "gotcha" games. If you want to discuss the actual issues of this thread, feel free. But if you want to play games and behave like an ass, don't waste my time.