Characterization and identification of dityrosine cross-linked peptides using tandem mass spectrometry

The use of mass spectrometry coupled with chemical cross-linking of proteins has become a powerful tool for proteins structure and interactions studies. Unlike structural analysis of proteins using chemical reagents specific for lysine or cysteine residues, identification of gas-phase fragmentation patterns of endogenous dityrosine cross-linked peptides have not been investigated. Dityrosine cross-linking in proteins and peptides are clinical markers of oxidative stress, aging, and neurodegenerative diseases including Alzheimer’s disease and Parkinson’s disease. In this study, we investigated and characterized the fragmentation pattern of a synthetically prepared dityrosine cross-linked dimer of Aβ(1–16) using ESI tandem mass spectrometry. We then detailed the fragmentation pattern of dityrosine cross-linked Aβ(1–16), using collision induced dissociation (CID), higher-energy collision induced dissociation (HCD), electron transfer dissociation (ETD), and electron capture dissociation (ECD). Application of these generic fragmentation rules of dityrosine cross-linked peptides allowed for the identification of dityrosine cross-links in peptides of Aβ and α-synuclein generated in vitro by enzymatic peroxidation. We report, for the first time, the dityrosine cross-linked residues in human hemoglobin and α-synuclein under oxidative conditions. Together these tools open up the potential for automated analysis of this naturally occurring post-translation modification in neurodegenerative diseases as well as other pathological conditions

The manoeuvrability and mobility increase of modular engines of the aviation flights airfield-technical ensuring

Впервые обосновывается возможность построения модульной машины с расположением одноосного прицепа с неповоротными колесами впереди тягача. Получен способ управления, обеспечивающий управляемость и устойчивость криволинейного движения такого автопоезда. Показана применимость разработанной методики и для обычного автопоезда с задним расположением прицепа при движении задним ходом.Вперше обґрунтовується можливість побудови модульної машини з розташуванням одновісного причепа з неповоротними колесами попереду тягача. Отриманий спосіб керування, що забезпечує управляємість та стійкість криволінійного руху такого автопотягу. Показана застосовуваність розробленої методики і для звичайного автопотягу з заднім розташуванням причепу при русі заднім ходом.The possibility of modular engine construction with the disposition of the monoaxial trailer with unrotary wheels in front of the prime mover is grounded for the first time. The way of driving, which provides controllability and steadiness of the curvilinear movement of the articulated truck of such a kind is obtained. The applicability of the developed methodology for the usual articulated truck with the back disposition of the trailer by reverse movement is shown