A1M: a heme and radical binding protein. A study on structure, function and mechanisms
Författare
Summary, in English
The research focus in this thesis has been to study the protection mechanisms of A1M with a special focus on the structure, and to investigate its protection properties in vivo.
The results show that radiation-induced cell damage induces reactive oxygen species (ROS) and that ROS mediates a so-called bystander effect (a spreading of damage to cells not directly hit by the radiation). A1M inhibited the bystander effect and by using site-directed mutagenesis it was shown that this protection is dependent on a cysteine side-chain in position 34, and regulated by three lysine residues in position 92, 118 and 130.
Furthermore, when A1M binds heme, the cysteine in position 34, a histidine in position 123, and the three lysine-residues in position 92, 118 and 130 are involved in co-ordination of the iron-atom in heme. The results support a model in which two heme-groups are bound simultaneously. Molecular simulation suggests binding of the first heme group inside the lipocalin pocket, followed by a structural shift that allows binding of a second heme group, with lower affinity, near the opening of pocket.
Finally, the in vivo therapeutic effects of A1M were investigated using a sheep model of the pregnancy disease preeclampsia. Starvation induced preeclampsia-like symptoms in the pregnant ewes manifesting in hemolysis and subsequent damage to the placenta and kidneys. A1M was well tolerated and displayed positive therapeutic effects.
Avdelning/ar
Publiceringsår
2014
Språk
Engelska
Publikation/Tidskrift/Serie
Lund University Faculty of Medicine Doctoral Dissertation Series
Volym
2014:139
Dokumenttyp
Doktorsavhandling
Förlag
Division of Infection Medicine
Ämne
- Infectious Medicine
Nyckelord
- α1-microglobulin
- oxidative stress
- heme
- radiation
- reactive oxygen species
- preeclampsia
Status
Published
Handledare
ISBN/ISSN/Övrigt
- ISSN: 1652-8220
- ISBN: 978-91-7619-068-5
Försvarsdatum
13 december 2014
Försvarstid
10:00
Försvarsplats
Belfrage, BMC D15, Klinikgatan 32, Lund
Opponent
- Maria D. Ganfornina (Professor)