Table 1.

The location and characteristics of fatty acid binding sites FA1-7 of albumin. Particular attention is drawn to binding site FA2, since occupation of this site by FFAs causes an allosteric switch in metal binding at site A, owing to its close proximity; both are located between subdomains IA and IIA.

Site	Affinity	Physiologicala	Subdomain	Comments	Reference
FA1	Low	–	IB	Site is relatively accessible to solvent	[79], [82]
FA2	High	Yes	IA-IIA	Allosteric switch affecting site A	[21], [82], [83]
FA3	Low	–	IIB-IIIA	Chain distorted in longer FFAs	[78], [82]
FA4	High	Yes	IIIA	Inverted configuration for C18 FFAs	[82], [83], [143]
FA5	High	Yes	IIIB	C18 FFAs accommodated	[82], [83]
FA6	Low	–	IIA-IIB	Absence of ligands for carboxylate	[78], [79], [82]
FA7	Low	–	IIA	Preference for shorter-chain FFAs	[78], [82]

^a(Partially) Occupied under basal physiological conditions (pH 7.4, 0.5–2 mol. equiv. of FFA).