Table 2. Interaction Analysis of Receptor–Ligand Interactions of (6-AcBTZ)2DTPA and Tc-(6-AcBTZ)2DTPA with 5-HT1A–5-HT7 Dimeric and Monomeric Receptorsa.
| receptor system | hydrophobic interactions | π–π stacking and π–cationinteractions | polar interaction | charged interactions | H-bond and salt bridge |
|---|---|---|---|---|---|
| 5-HT1A–5-HT1A homodimer | chain A: Trp102, Leu104, Pro184, Leu99, Val107, Leu95, Ala94, Pro91, Ile47, Leu43, Leu41 | chain A: Asn100, Thr103, Gln106, Thr108, Ser40 | chain A: Lys101, Asp185 | chain A: Lys101 | |
| chain B: Leu43, Ala94, Leu95, Val98, Leu99, Leu104, Pro184, Ile47 | chain B: Gln36, Ser40, Thr103 | chain B: Lys101, Asp185 | chain B: Gln36 | ||
| 5-HT7–5-HT7 homodimer | chain A: Tyr76, Ile74, Ile144, Trp148, Ile149 | chain B: Tyr249 | chain A: Asn75, Gln73, Thr141, His152 | chain A: Lys147, Arg78, Asp142 | chain A: Asn75, Lys147, Trp148, Ile149, His152, Gly14 |
| chain B: Phe237, Ile241, Tyr242, Ala245, Phe352, Ala349, Leu346, Leu345, Tyr249, Tyr249, Leu256 | chain B: Thr348, Ser253 | ||||
| 5-HT1A–5-HT7 heterodimer | |||||
| 5-HT1A pocket | Phe370, Cys371, Leu380, Leu381, Ile384, Ile385, Tyr96, Pro348, Ala383, Leu388, Val367, Ile189, Ala186 | Phe370, Hip193 | Thr196, Ser374, Ser190, Thr188, Asn100, Gln97, Thr379, Hie193, Ser190, Ser182 | Arg181, Asp180, Glu179, Hip193, Asp192, Lys191, Asp183 | Thr188, Leu380, Lys191 |
| 5-HT7 pocket | Val230, Leu232, Phe237, Pro351, Trp364, Leu363, Pro362, Ile361, Cys360, Val225, Cys354, Ile233, Tyr239, Val163, Phe344, Phe343, Ala247 | Phe343 | Asn226, Ser234, Gln235, Thr240, Thr244, Ser243, Ser347 | Asp227, Asp228, Lys229, Asp236, Arg350, Arg367, Glu365, | Leu363, Asn226, Gln235, Arg350 |
| 5-HT1A monomer | Phe370, Val367, Ile363, Trp387, Ile384, Ala383, Leu381, Leu380, Pro378, Ala186, Cys187, Ile189, Tyr96 | Thr188, Thr379, Asn100, Gln97, Ser182, Ser190, Ser374 | Asp185, Lys191, Lys101, Asp180, Glu179, Arg181, Asp192, Hip193 | Leu381, Tyr96, Hip193, Lys191, Ile189, Cys187, Asp180 | |
| 5-HT7 monomer | Val230, Leu232, Ile233, Phe237, Val163, Cys166, Phe343, Phe344, Pro351, Cys354, Cys360, Ile361, Leu363, Val225, Phe343, Ala247, Tyr239 | Phe343 | Asn226, Ser234, Gln235, Thr240, Ser243, Thr244, Ser347 | Glu366, Arg350, Asp236, Asp228, Asp227 | Arg350, Cys354, Gln235, Ser243 |
a
Italic text: interactions observed with Tc-(6-AcBTZ)2DTPA; bold normal text: common interactions between (6-AcBTZ)2DTPA and Tc-(6-AcBTZ)2DTPA ligands; normal text: interactions of (6-AcBTZ)2DTPA.