Crystal structure of human serum albumin at 2.5 A resolution.
A new triclinic crystal form of human serum albumin (HSA), derived either from pool plasma (pHSA) or from a Pichia pastoris expression system (rHSA), was obtained from polyethylene glycol 4000 solution. Three-dimensional structures of pHSA and rHSA were determined at 2.5 A resolution from the new triclinic crystal form by molecular replacement, using atomic coordinates derived from a multiple isomorphous replacement work with a known tetragonal crystal form. The structures of pHSA and rHSA are virtually identical, with an r.m. s. deviation of 0.24 A for all Calpha atoms. The two HSA molecules involved in the asymmetric unit are related by a strict local twofold symmetry such that the Calpha atoms of the two molecules can be superimposed with an r.m.s. deviation of 0.28 A in pHSA. Cys34 is the only cysteine with a free sulfhydryl group which does not participate in a disulfide linkage with any external ligand. Domains II and III both have a pocket formed mostly of hydrophobic and positively charged residues and in which a very wide range of compounds may be accommodated. Three tentative binding sites for long-chain fatty acids, each with different surroundings, are located at the surface of each domain.
Sugio
S
S
Osaka Laboratories, Yoshitomi Pharmaceutical Industries Ltd,2-25-1, Shodai-Ohtani, Hirakata, Osaka 573-1153, Japan.
Kashima
A
A
Mochizuki
S
S
Noda
M
M
Kobayashi
K
K
D001665:Binding Sites; D003460:Crystallization; D018360:Crystallography, X-Ray; D004220:Disulfides / Q000737:chemistry; D006801:Humans; D008958:Models, Molecular; D010843:Pichia / Q000378:metabolism; D017433:Protein Structure, Secondary; D017434:Protein Structure, Tertiary; D011994:Recombinant Proteins / Q000737:chemistry; D012709:Serum Albumin / Q000737:chemistry* / Q000378:metabolism; D013438:Sulfhydryl Compounds / Q000737:chemistry
D004220:Disulfides; D011994:Recombinant Proteins; D012709:Serum Albumin; D013438:Sulfhydryl Compounds