Biochem/physiol Actions
Blood-brain barrier (BBB)-permeable, far-red (near-IR) fluorescent contrast agent for staining of amyloid plaques with high specificity in situ and in vivo.
NIAD-4 is a blood-brain barrier (BBB)-permeable, far-red (near-IR) fluorescent contrast agent for staining of amyloid plaques with high specificity in situ (10 μM in DMSO/propylene glycol; APP mice coronal section) and in vivo (2 mg/kg APP mice i.v.). Due to its push-pull structure design and a greatly enhanced thioflavin T (ThT) site affinity (Ki = 10 nM/NIAD-4 vs 580 nM/ThT), NIAD-4 exhibits significantly red-shifted (~70 nm) absorption and a 1.3-fold increase in extinction coefficient upon binding aggregated amyloid-beta 1-40 (4.1 μM NIAD-4 & 10 μM amyloid-β in PBS). Ex 450-488 nm, Em 550-650 nm.