Table 4.

Sequences of BBN15–18 and their reported biological properties [89].

Comp.	Sequence b	Stability after 48 h [%] c,d	Uptake after 4 h [%] d,e	KD [nM] f
BBN15 a	[177Lu]Lu-DOTA-PEG4-d-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-Leu	65	30	2.7
BBN16	[177Lu]Lu-DOTA-PEG4-d-Phe-Gln-Trp-Ala-Val-Gly-His-Sta-LeuΨ[Tz]H	75	13	8.1
BBN17	[177Lu]Lu-DOTA-PEG4-d-Phe-Gln-Trp-Ala-Val-GlyΨ[Tz]His-Sta-Leu	n.d.	n.d.	>1000
BBN18	[177Lu]Lu-DOTA-PEG4-d-Phe-Gln-Trp-AlaΨ[Tz]Val-Gly-His-Sta-Leu	n.d.	n.d.	>1000

^a Reference compound. ^b Sta: statine: (3S,4S)-4-amino-3-hydroxy-6-methylheptanoic acid. ^c Determined in blood serum at 37 °C. Expressed as % of intact peptide. ^d n.d.: not determined ^e Ratio of specific receptor-bound and cell-internalised compound expressed in % of administered dose. Expressed as the means of three independent experiments. ^f Determined by receptor saturation binding assay on PC3 cells expressing GRPr. Expressed as the means ± SEM of at least two independent experiments.