1. Reengineering a type II beta-turn as a potential helix nucleator. Part I. Crystal structure of Boc-Val-Pro-(D)Asp-Asp-Val-OMe monohydrate
F Fabiola, V Pattabhi, E B Raju, S Durani J Pept Res. 1997 Nov;50(5):352-6. doi: 10.1111/j.1399-3011.1997.tb01194.x.
The crystal structure of Boc-Val1-Pro2-(D)Asp3-Asp4-Val5-OMe is described as a type II beta-turn reengineered into a potential helix nucleator. (D)Asp3 in the peptide is responsible for the configurationally guided LD chiral type II beta-turn centered at Pro2-(D)Asp3, as well as the partially developed LL chiral type I beta-turn centered at Asp4-Val5 by acceptance of a conformation nucleating H-bond from Val5NH to its carboxylic oxygen.
2. Crystal structure of N-{ N-[ N-( tert-but-oxy-carbon-yl)-l-α-aspart-yl]-l-α-aspart-yl}-l-α-aspartic acid 14,24,34-trimethyl ester 31-2-oxo-2-phenyl-ethyl ester {Boc-[Asp(OMe)]3-OPac}
Takuma Kato, Saki Kishimoto, Akiko Asano, Mitsunobu Doi Acta Crystallogr E Crystallogr Commun. 2019 Apr 9;75(Pt 5):585-588. doi: 10.1107/S2056989019004596. eCollection 2019 May 1.
In the title homotripeptide {Boc-[Asp(OMe)]3-OPac}, C28H37N3O13, all peptide bonds adopt an s-trans conformation with respect to the N-H and C=O groups. In the crystal, N-H⋯O hydrogen bonds result in an infinite parallel β-sheet structure running along the b-axis direction. The Boc protecting group at the N-terminus of the peptide is disordered over two sites with occupancy factors of 0.504 (5) and 0.496 (5).
3. Neuroprotection of grafted neurons with a GDNF/caspase inhibitor cocktail
C E Helt, G R Hoernig, D S Albeck, G A Gerhardt, B Ickes, M E Reyland, D O Quissell, I Strömberg, A C Granholm Exp Neurol. 2001 Aug;170(2):258-69. doi: 10.1006/exnr.2001.7709.
Transplantation of fetal ventral mesencephalic (VM) tissue shows great promise as an experimental therapy for patients with Parkinson's disease. However, cell survival in brain tissue grafts is poor, with survival rates of only 5-15%. We have utilized a combination of the caspase inhibitor bocaspartyl (OMe)-fluoromethylketone (BOC-ASP-CH2F) and glial cell line-derived neurotrophic factor (GDNF) to enhance survival of grafted dopamine neurons. The VM tissue was dissected from embryonic day 13-15 rat fetuses, incubated in different doses of BOC-ASP-CH2F and GDNF, and transplanted to the anterior chamber of the eye of adult rats. Growth of the tissue was assessed through the translucent cornea. Doses of 50 and 100 micromolar of the general caspase inhibitor appeared to have detrimental effects on mesencephalic tissue, while 20 micromolar had beneficial effects on overall transplant growth. A combination of the caspase inhibitor and GDNF appeared to have more prominent effects on cell survival as well as dopaminergic fiber density than either agent by itself. The transplants doubled in size when they were treated with a combination of BOC-ASP-CH2F and GDNF, and cell death markers were significantly reduced at both 48 h and 4-6 days postgrafting. This is, to our knowledge, the first combined approach using apoptotic blockers with trophic factors, and demonstrates a viable strategy for protection of developing neurons, since several different aspects of graft function may be addressed simultaneously.
