TY - JOUR
T1 - Relative stability of α-melanotropin and related analogues to rat brain homogenates
AU - Akiyama, Kazufumi
AU - Yamamura, Henry I.
AU - Wilkes, Brian C.
AU - Cody, Wayne L.
AU - Hruby, Victor J.
AU - Castrucci, Ana Maria de L.
AU - Hadley, Mac E.
PY - 1984
Y1 - 1984
N2 - α-Melanotropin (α-MSH) retains less than 1% of its original activity after a 60 min incubation with 10% rat brain homogenate. [Nle4, D-Phe7]-α-MSH is nonbiodegradable in rat serum (240 min incubation) and still maintains 10% of its original activity in 10% rat brain homogenate (240 min incubation). The related fragment analogue, Ac-[Nle4, D-Phe7]-α-MSH4-10-NH2, retains 50% of its activity after a 240 min incubation in rat brain homogenate, whereas Ac-[Nle4, D-Phe7]-α-MSH4-11-NH2 is totally resistant to inactivation by rat brain homogenate. Both [Nle4, D-Phe7]-fragments are resistant to degradation by rat serum, but [Nle4]-α-MSH, Ac-[Nle4]-α-MSH4-10-NH2 and Ac-[Nle4]-α-MSH4-11-NH2 are rapidly inactivated under both conditions. The cyclic melanotropin, [Cys4,Cys10]-α-MSH, is inactivated in rat brain homogenate as is the shorter Ac-[Cys4,Cys10]-α-MSH4-10-NH2 analogue, but neither cyclic melanotropin is inactivated upon incubation in serum from rats. Ac-[Cys4,D-Phe7,Cys10]-α-MSH4-10-NH2 is resistant to inactivation by either rat serum or a brain homogenate. Some of these melanotropin analogues may provide useful probes for the localization and characterization of putative melanotropin receptors in both the central nervous system and peripheral tissues.
AB - α-Melanotropin (α-MSH) retains less than 1% of its original activity after a 60 min incubation with 10% rat brain homogenate. [Nle4, D-Phe7]-α-MSH is nonbiodegradable in rat serum (240 min incubation) and still maintains 10% of its original activity in 10% rat brain homogenate (240 min incubation). The related fragment analogue, Ac-[Nle4, D-Phe7]-α-MSH4-10-NH2, retains 50% of its activity after a 240 min incubation in rat brain homogenate, whereas Ac-[Nle4, D-Phe7]-α-MSH4-11-NH2 is totally resistant to inactivation by rat brain homogenate. Both [Nle4, D-Phe7]-fragments are resistant to degradation by rat serum, but [Nle4]-α-MSH, Ac-[Nle4]-α-MSH4-10-NH2 and Ac-[Nle4]-α-MSH4-11-NH2 are rapidly inactivated under both conditions. The cyclic melanotropin, [Cys4,Cys10]-α-MSH, is inactivated in rat brain homogenate as is the shorter Ac-[Cys4,Cys10]-α-MSH4-10-NH2 analogue, but neither cyclic melanotropin is inactivated upon incubation in serum from rats. Ac-[Cys4,D-Phe7,Cys10]-α-MSH4-10-NH2 is resistant to inactivation by either rat serum or a brain homogenate. Some of these melanotropin analogues may provide useful probes for the localization and characterization of putative melanotropin receptors in both the central nervous system and peripheral tissues.
KW - Brain
KW - Hormone stability
KW - Melanocyctes
KW - Melanocyte stimulating hormone
KW - Melanotropins
KW - α-MSH
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U2 - 10.1016/0196-9781(84)90186-4
DO - 10.1016/0196-9781(84)90186-4
M3 - Article
C2 - 6531272
AN - SCOPUS:0021712174
VL - 5
SP - 1191
EP - 1195
JO - Peptides
JF - Peptides
SN - 0196-9781
IS - 6
ER -