Specific interactions between the human serotonin transporter and serotonin analogs at the solution/air interface

• Published in: Colloids and surfaces, B, Biointerfaces Vol. 9; no. 3; pp. 197 - 203
• Main Authors: Dalençon, F., Rosilio, V., Manivet, P., Launay, J.-M., Baszkin, A.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 31-07-1997
• Subjects: Binding of serotonin analogs; Serotonin; Serotonin transporter (SERT); Spread protein monolayers; Surface pressure measurements; Spread protein monolayers; Surface pressure measurements; Binding of serotonin analogs; Serotonin; Serotonin transporter (SERT)
• ISSN: 0927-7765; 1873-4367
• DOI: 10.1016/S0927-7765(97)00030-1

Purified serotonin transporter protein (SERT) was spread at the buffer solution/air interface. The monolayers appeared to be stable and exhibited an inflection point at
π
m = 15 mN m
−1 and
A
m
= 3302
A
̊
2
which has been considered as the maximum pressure below which the protein preserved its initial conformation.
Specific interactions between SERT and serotonin (5-HT) or its analogs (5-HTP, 5-HTOL, 5-HIAA, indalpine) have been assessed by measuring the increase in the initial surface pressure of a SERT monolayer (
π
i = 7.5 mN m
−1) on injection of its ligands into the equeous subphase.
The strongest interaction was that observed with indalpine; this was attributed to the presence of an easily accessible amine function in position 3 of the indole ring of this molecule. Since no significant interaction between SERT and serotonin was observed, it has been inferred that the SERT conformation at the solution/air interface did not allow this interaction to occur due to the inaccessibility of the corresponding specific site.