For protein, sequencing questions, ask for guidance As long as there is clarity, be sure to add 80 p

That's all you need to do when composing questions:

1.Acid hydrolysis is commonly used for hydrolysis by H2SO4 or HCl. Disadvantages: Tryptophan is completely broken down, asparagine and glutamine are turned into aspartic acid and glutamic acid. (Proteins are hydrolyzed into amino acids one by one).

2.Alkaline hydrolysis Only tryptophan is stable and everything else is hydrolyzed. If ornithine or urea is present in the hydrolysate, it proves that arginine was present before hydrolysis. (Proteins are hydrolyzed into amino acids one by one).

3.Trypsin hydrolysis breaks only the carboxyl group of lysine or arginine residues to participate in the formation of peptide bonds. If the amino acid sequence is written according to the international standard (i.e., from the N-terminus to the C-terminus), then this enzyme hydrolyzes the peptide bond to the right of the lys or arg that is linked to the next amino acid.

For example, the plot shows that the cleavage site is "|".”asp-lys-|-gly。(Protein cleaves from the break site into a polypeptide).

4.Myrosoptease hydrolysis breaks the carboxy-terminal peptide bonds of hydrophobic amino acid residues of Phe, TRP, and TYR. That is, the peptide bond on the right side of Phe, TRP, and TYR is broken and connected to the next amino acid. (Protein cleaves from the break site into a polypeptide).

5.Thermophilic protease hydrolysis breaks the aminotelopeptide bonds of Leu, Ile (isoleucine), PHE, TRP, VAL, TYR, or MET amino acid residues. That is, the peptide bond of Leu, Ile, Phe, TRP, Val, Tyr, or Met is broken to the left of the previous amino acid.

Generally, this enzyme rarely appears in the questions, and it is almost impossible to test it, unless the teacher wants to deliberately embarrass you. (Protein cleaves from the break site into a polypeptide).

6.Pepsin hydrolysis breaks the peptide bond between two hydrophobic amino acids (PHE, LEU, TRP, TYR). Such as peptide bonds between Phe-Phe, Phe-TRP.

These hydrolases, which are not very specific, are not included in the general exam questions. (Protein cleaves from the break site into a polypeptide).

7.Cyanogen bromide fracture first famous, see clearly, which cyanide of cyanide bromide is, don't look at hydrogen as hydrogen! Only the carboxy-terminal peptide bond of the methionine residue is broken.

The latter sentence is known and known) After the breakage, methionine becomes peptidoyl homoserine lactone. (Protein cleaves from the break site into a polypeptide).

8.Hydroxylamine (NH2OH) cleavage Specifically breaks the peptide bond between ASN-GLY. (Protein cleaves from the break site into a polypeptide).

In fact, some of the enzymes or chemicals above are not only hydrolyzed by the sites I listed, but they are generally not considered during the exam.

1. The sample must be pure (> more than 97%);

2 Know the molecular weight of the protein;

3 Know that proteins are made up of several wild land subunits;

4. Determination of the high-quality amino acid composition of protein Kaiji; The number of each amino acid is calculated according to the molecular weight.

5. Determine the amount of ammonia in the hydrolysate and calculate the content of amide.