Differential metabolism of dynorphins in substantia nigra, striatum, and hippocampus.
To map the proteolytic enzymes metabolizing dynorphins in brain structures, size-exclusion chromatography linked to electrospray ionization mass spectrometry was used. Enzymes extracted from rat hippocampus, striatum, and substantia nigra were tested for their capability of converting dynorphin-related peptides. Dynorphin A was the most resistant to proteolytic conversion, whereas Big dynorphin and dynorphin B-29 were slowly converted to dynorphin A and dynorphins A and B, respectively. Dynorphin B and alpha-neoendorphin were the least resistant. Dynorphin B was rapidly converted to Leu-enkephalin in the striatum and hippocampus but to Leu-enkephalin-Arg6 in the substantia nigra. alpha-Neoendorphin was converted to Leu-enkephalin in all tissues investigated.
Sandin
J
J
Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden. johasa@cmm.ki.se
Tan-No
K
K
Kasakov
L
L
Nylander
I
I
Winter
A
A
Silberring
J
J
Terenius
L
L
D000595:Amino Acid Sequence; D000818:Animals; D002851:Chromatography, High Pressure Liquid; D003342:Corpus Striatum / Q000378:metabolism*; D004399:Dynorphins / Q000737:chemistry / Q000378:metabolism*; D004723:Endorphins / Q000737:chemistry / Q000378:metabolism; D004743:Enkephalin, Leucine / Q000031:analogs & derivatives / Q000737:chemistry / Q000378:metabolism; D006624:Hippocampus / Q000378:metabolism*; D008297:Male; D013058:Mass Spectrometry; D011498:Protein Precursors / Q000737:chemistry / Q000378:metabolism; D051381:Rats; D013378:Substantia Nigra / Q000378:metabolism*; D014018:Tissue Distribution
D004723:Endorphins; D011498:Protein Precursors; D004743:Enkephalin, Leucine; D004399:Dynorphins; C026768:enkephalin-Leu, Arg(6)-; C036200:rimorphin