Map · Energy metabolism · Ketolysis

Ketolysis extrahepatic use of ketone bodies · 2 enzymes

Acetoacetate is activated by CoA-transfer from succinyl-CoA, then thiolyzed to two acetyl-CoA. Liver lacks OXCT1, so it does not consume the ketones it makes. ACAT1 here is the thiolysis direction — own URL, same 2IBY mesh.

Ketolysis — extrahepatic use of ketone bodies (2 enzymes)

Acetoacetate is activated by CoA-transfer from succinyl-CoA, then thiolyzed to two acetyl-CoA. Liver lacks OXCT1, so it does not consume the ketones it makes. ACAT1 here is the thiolysis direction — a separate page from ketogenesis ACAT1, same 2IBY mesh.

ACETOACETATE
①
KETOLYSIS 1

Succinyl-CoA:3-ketoacid CoA-transferase OXCT1 · SCOT

acetoacetate + succinyl-CoA → acetoacetyl-CoA + succinate

Ping-pong CoA-transfer on 3DLX. Occupancy is glycerol only — never label GOL as substrate. Entry is To be Published; cite RCSB 3DLX, no PMID.

EC 2.8.3.5 · PDB 3DLX

▶ OPEN SIMULATOR
→
acetoacetyl-CoA
KETOLYSIS 2

Mitochondrial acetoacetyl-CoA thiolase ACAT1 · T2 · thiolysis

acetoacetyl-CoA + CoA → 2 acetyl-CoA

Same enzyme as ketogenesis step 1, opposite teaching direction, own URL. Occupancy is still free CoA on 2IBY. Not ACAA2 (T1, β-ox).

EC 2.3.1.9 · PDB 2IBY

▶ OPEN SIMULATOR
→
2 ACETYL-CoA
⤷ Acetyl-CoA from ketolysis enters extrahepatic TCA. D-BHB is first oxidized by BDH1 (ketogenesis page, reverse read) before OXCT1.