Abstract

Oral Sessions

Day 3, May 17（Fri.）　16:25-16:45　Room D (202)

3D-O2-1625　　PDF

Proline Effect and Intramolecular Hydrogen Transfer in CID of Peptide

(¹Yokohama City Univ., ²Shimadzu)
^oMitsuo Takayama¹, Asaki Kagpshima¹, Sadanori Sekiya², Shinichi Iwamoto², Koichi Tanaka²

Intramolecular hydrogen transfer to form [y+2H]⁺ ions formed by the proline effect in low- and high-energy (E) CID experiments are examined using a synthetic peptide EGV-d5 containing deuterated Ala(d3)-Pro and Gly(d2)-Pro residues. The high-E CID resulted in [y]⁺ and [y+2H]⁺ ions originated from cleavage at the Xxx-Pro residues, while low-E CID merely resulted in the [y+2H]⁺ ions. The rates of deuterium (hydrogen) transfer from alpha-carbon (Gly-d2), beta-carbon (Ala-d3) and other sites to form [y+HD]⁺ and [y+2H]⁺ are estimated from the isotope patterns of y-related ions. The mechanism for the formation of [b]⁺, [y]⁺ and [y+2H]⁺ ions due to the proline effect also is described in both low- and high-E CID experiments.