Formation of a 2-methyl-branched fatty aldehyde during peroxisomal alpha-oxidation.
In the final reaction of peroxisomal alpha-oxidation of 3-methyl-branched fatty acids a 2-hydroxy-3-methylacyl-CoA intermediate is cleaved to formyl-CoA and a hitherto unidentified product. The release of formyl-CoA suggests that the unidentified product may be a fatty aldehyde. When purified rat liver peroxisomes were incubated with 2-hydroxy-3-methylhexadecanoyl-CoA 2-methylpentadecanal was indeed formed. The production rates of formyl-CoA (measured as formate) and of the aldehyde were in the same range. While the production of formate remained unaltered in the presence of NAD+, the amount of 2-methylpentadecanal was decreased, which was accompanied by the formation of 2-methylpentadecanoic acid. These data indicate that (1) during alpha-oxidation the 2-hydroxy-3-methylacyl-CoA is cleaved to a 2-methyl-branched aldehyde and formyl-CoA and (2) liver peroxisomes are capable of converting this aldehyde to a 2-methyl-branched fatty acid.
Croes
K
K
Katholieke Universiteit Leuven, Afdeling Farmacologie, Campus Gasthuisberg, Belgium.
Casteels
M
M
Asselberghs
S
S
Herdewijn
P
P
Mannaerts
G P
GP
Van Veldhoven
P P
PP
D000445:Aldehyde Oxidoreductases / Q000378:metabolism; D000447:Aldehydes / Q000737:chemistry / Q000378:metabolism*; D000818:Animals; D015227:Lipid Peroxidation; D008099:Liver / Q000737:chemistry / Q000378:metabolism; D008297:Male; D008830:Microbodies / Q000737:chemistry / Q000378:metabolism*; D010169:Palmitic Acids / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012663:Semicarbazides
D000447:Aldehydes; D010169:Palmitic Acids; D012663:Semicarbazides; C034839:2-methylhexadecanoic acid; C010059:carbamylhydrazine; D000445:Aldehyde Oxidoreductases; C038828:long-chain-aldehyde dehydrogenase