## 3 Experimental Section
### Synthesis  
#### Conventional Solid Phase Peptide Synthesis (SPPS) of Linear Peptides  
The synthesis of [Ala\({}^{41}\)]MOG\({}_{35-55}\), [Ala\({}^{41,46}\)]MOG\({}_{35-55}\) and [TyrOMe\({}^{40}\)]MOG\({}_{35-55}\) was performed on CLTR-Cl resin (3 g). The first N\({}^{*}\)-9-fluoreylmethyloxycarbonyl (Fmoc) protected amino acid, Fmoc-Lys(Boc)-OH (4.5 equiv.), was esterified to the resin in the presence of diisopropyllyamine (DIEA, 13.5 equiv.) in dichloromethane (DCM, 20 mL) for 1.5 h at RT (room temperature). Subsequently methanol (MeOH, 3 mL) and DIEA (1.5 mL) were added and the mixture stirred for 30 min at RT. The remaining active site of the resin was capped using a mixture of DCM/MeOH/DIEA (85:10:5) at RT. The resin was washed with _N,N_-dimethylformamide (DMF, 3 times \(\times\) 5 mL) and isopropanol (_i_-PrOH, 3 times \(\times\) 5 mL) following by the Fmoc deprotection with the 25% piperidine in DMF solution (2 times for 10 min and 30 min) and dried overnight under vacuum. The substitution level, measured by the weight increase, after the first coupling and Fmoc deprotection, was 0.72 mmol/g resin.  
The remaining peptide chain was assembled by sequential couplings of the following Fmoc protected amino acids (5.4 equiv.) that were protected in side chain with _tert_-Butyl (tBu), Trityl (Trt) and 2,2,4,6,7-pentamethyldihydrobenzofuran-5-sulfonyl (Pbf): Fmoc-Gly-OH, Fmoc-Asn(Trt)-OH, Fmoc-Arg(Pbf)-OH, Fmoc-Tyr(tBu)-OH, Fmoc-Leu-OH, Fmoc-His(Trt)-OH, Fmoc-Val-OH, Fmoc-Val-OH in the presence of _N,N'_-diisopropylcarbodiimide (DIC) (5.94 equiv.) and 1-hydroxybenzotriazole (HOBt) (8.1 equiv.) in dimethylacetamide (DMAC) for 4-6 h, followed by Fmoc deprotection with piperidine (two times with 25% in DMF for 10 min, and 30 min). The completeness of each coupling and Fmoc deprotection step was verified by the Kaiser test and thin layer chromatography (TLC) using _n_-butanol (1-BuOH)-acetic acid (AcOH)-water (H\({}_{2}\)O) (4:1:1), toluene (Tol)-MeOH-AcOH (7:1.5:1.5) and acetonitrile (ACN)-H\({}_{2}\)O (5:1) as eluent systems. After the couplings of the first nine amino acids, the resin was splitted to three equal amount in separate reactors for the synthesis of the [Ala\({}^{41}\)]MOG\({}_{35-55}\), [Ala\({}^{41,46}\)]MOG\({}_{35-55}\) and [TyrOMe\({}^{40}\)]MOG\({}_{35-55}\) peptides following the described methodology. The following Fmoc protected amino acids were used: (i) [Ala\({}^{41}\)]MOG\({}_{35-55}\): (1.8 equiv) Fmoc-Arg(Pbf)-OH, Fmoc-Ser(tBu)-OH, Fmoc-Phe-OH, Fmoc-Pro-OH, Fmoc-Pro-OH, Fmoc-Ala-OH, Fmoc-Tyr(tBu)-OH, Fmoc-Trp(Boc)-OH, Fmoc-Gly-OH, Fmoc-Val-OH, Fmoc-Glu(tBu)-OH and Fmoc-Met-OH; (ii) [Ala\({}^{41,46}\)]MOG\({}_{35-55}\): (1.8 equiv) Fmoc-Ala-OH,Fmoc-Ser(tBu)-OH, Fmoc-Phe-OH, Fmoc-Pro-OH, Fmoc-Pro-OH, Fmoc-Ala-OH, Fmoc-Tyrt(Bu)-OH, Fmoc-Tyrt(Bu)-OH, Fmoc-Tyrt(Bu)-OH, Fmoc-Gly-OH, Fmoc-Val-OH, Fmoc-Glut(Bu)-OH and Fmoc-Met-OH and (iii) [TyrOMe40]MOG35-55: (1.8 equiv) Fmoc-Arg(Pbf)-OH, Fmoc-Ser(tBu)-OH, Fmoc-Phe-OH, Fmoc-Pro-OH, Fmoc-Arg(Pbf)-OH, Fmoc-Tyr(OMe)-OH, Fmoc-Tyr(Boc)-OH, Fmoc-Gly-OH, Fmoc-Val-OH, Fmoc-Glut(Bu)-OH and Fmoc-Met-OH.  
Cleavage from the Resin and Final Deprotection  
After completing the synthesis of each peptide, the resin was cleaved with the splitting solution DCM/2,2,2-trifluoroethanol ( TFE) (7:3) for 1.5 h at RT. The final deprotection of each peptide was achieved using a trifluoroacetic acid (TFA)/DCM/triethylsilane(TES)/1,2-ethanedithiol(EDT)/anisole/H\({}_{2}\)O (90:4:2:2:1:1) solution for 5 h at RT. The solvent was removed by evaporation and each peptide precipitated with cold diethyl ether. The final amounts of the crude synthesized peptides were: (i) 0.176 g of [Ala41]MOG35-55; (ii) 0.146 g of [Ala41, 46]MOG35-55 and (iii) 0.1 g of [TyrOMe40]MOG35-55.