Cardiovascular effects of PACAP and PACAP(6â38) in the RVLM of normotensive and hypertensive rats. A and B: changes in mean arterial pressure (MAP; i), HR (ii), and percentage of sSNA (iii) before and after the administration of PACAP (A) or PACAP(6â38) (B). Arrows indicate times of drug infusion. âPBSâ indicates the period after the bilateral RVLM microinjection of PBS; âPACAPâ and âPACAP(6â38)â indicate the periods after the bilateral RVLM microinjection of PACAP or PACAP(6â38), respectively. C: comparison of maximum MAP (i), HR (ii), and percentage of sSNA responses (iii) after PACAP or PACAP(6â38). *P < ; **P < ; ***P < .
a) Cyanogen bromide cleavage gives two peptide fragments, the longer of which has all the units on the C-terminal side of methionine.
b) N-terminal analysis of the undecapeptide fragment, P 11 , locates the three amino acids to the right of methionine.
c) Trypsin cleavage of P 11 shows the location of the single arginine, which is found as the C-terminal unit of the tetrapeptide fragment. One of the two lysines was known to be next to the C-terminus. The other must be part of the smaller peptide from the cyanogen bromide reaction.
d) With only four amino acids remaining to be located, the position of the second tyrosine may be pursued by chymotrypsin cleavage of P 18 itself. Four fragments are obtained, and the final structure might have been solved by these alone. However, selective terminal group analysis of the two pentapeptides serves to locate the tyrosine and a second proline next to the left most glycine, as well as identifying the units on each side of the methionine. The one remaining amino acid, a proline, is then placed at the last vacant site (yellow box).