9PUO: Neutralizing monoclonal antibody Fab fragment

Neutralizing monoclonal antibody Fab fragment bound to leptin. Determined by X-ray diffraction at 3.1 Å resolution. Released 5 Nov 2025.

Method: X-ray diffraction
Resolution: 3.1 Å
Organism: Homo sapiens
Chains: 6
Atoms: 8,152
Mol. weight: 125.39 kDa
Ligands: PO4
Released: 5 Nov 2025

Explore 9PUO in 3D Show helices and sheets RCSB PDB PDBe

Secondary structure: helices and β-sheets

9PUO contains 32 α-helices and 91 β-strands across 6 chains. Residue ranges use author residue numbering, as in the PDB file, from PDBe. To see them in 3D, choose the Cartoon representation with Secondary structure coloring: helices, sheets and coils get different colors.

Chain A: 5 helices, 21 β-strands

Element	Residues	Length	Sheet
β-strand	4-6	3	1
β-strand	10-12	3	2
β-strand	18-24	7	1
β-strand	34-39	6	2
β-strand	45-51	7	2
β-strand	58-60	3	2
β-strand	68-73	6	1
β-strand	78-83	6	1
α-helix	88-90	3
β-strand	92-99	8	2
β-strand	109-112	4	2
β-strand	116-120	5	2
β-strand	126	1	3
α-helix	127-128	2
β-strand	129-133	5	4
β-strand	144-154	11	4
β-strand	155	1	3
β-strand	160-163	4	5
α-helix	164-166	3
β-strand	172-174	3	4
α-helix	175-177	3
β-strand	178-179	2	4
β-strand	185-194	10	4
α-helix	195-198	4
β-strand	204-209	6	5
β-strand	214-219	6	5

Chain B: 6 helices, 25 β-strands

Element	Residues	Length	Sheet
β-strand	4	1	6
β-strand	5	1	7
β-strand	9-12	4	8
β-strand	18-23	6	7
β-strand	35-40	6	8
β-strand	47-50	4	8
β-strand	51	1	9
β-strand	55	1	9
β-strand	64-69	6	7
β-strand	72-77	6	7
α-helix	82-84	3
β-strand	86-94	9	8
β-strand	99-102	4	8
β-strand	103	1	6
β-strand	106-110	5	8
β-strand	116	1	10
α-helix	117-118	2
β-strand	119-123	5	11
α-helix	127-131	5
β-strand	135-142	8	11
β-strand	145	1	10
β-strand	150-155	6	12
β-strand	158-160	3	12
β-strand	164-166	3	11
α-helix	167-169	3
β-strand	170-171	2	11
α-helix	172	1
β-strand	177-185	9	11
α-helix	187-192	6
β-strand	196-202	7	12
β-strand	205-211	7	12

Chain C: 5 helices, 0 β-strands

Element	Residues	Length
α-helix	3-24	22
α-helix	51-66	16
α-helix	71-93	23
α-helix	110-115	6
α-helix	122-141	20

Chain D: 5 helices, 22 β-strands

Element	Residues	Length	Sheet
β-strand	4-6	3	13
β-strand	10-12	3	14
β-strand	18-24	7	13
β-strand	34-39	6	14
β-strand	45-51	7	14
β-strand	58-60	3	14
β-strand	68-73	6	13
β-strand	78-83	6	13
α-helix	88-90	3
β-strand	92-99	8	14
β-strand	109-112	4	14
β-strand	116-120	5	14
β-strand	126	1	15
α-helix	127-128	2
β-strand	129-133	5	16
β-strand	144-154	11	16
β-strand	155	1	15
β-strand	160-163	4	17
α-helix	164-166	3
β-strand	168	1	17
β-strand	172-174	3	16
α-helix	175-177	3
β-strand	178-179	2	16
β-strand	185-194	10	16
α-helix	195-197	3
β-strand	204-209	6	17
β-strand	214-219	6	17

Chain E: 7 helices, 23 β-strands

Element	Residues	Length	Sheet
β-strand	4	1	18
β-strand	5	1	19
β-strand	9-12	4	20
β-strand	18-23	6	19
β-strand	36-40	5	20
α-helix	45-46	2
β-strand	47-50	4	20
β-strand	51	1	21
β-strand	55	1	21
β-strand	64-69	6	19
β-strand	72-77	6	19
α-helix	82-84	3
β-strand	86-94	9	20
β-strand	99-102	4	20
β-strand	103	1	18
β-strand	106-110	5	20
β-strand	119-123	5	22
α-helix	127-131	5
β-strand	135-142	8	22
β-strand	150-155	6	23
β-strand	158-159	2	23
α-helix	160	1
β-strand	164-166	3	22
α-helix	167-169	3
β-strand	170	1	22
α-helix	171-172	2
β-strand	178-185	8	22
α-helix	187-192	6
β-strand	196-202	7	23
β-strand	205-211	7	23

Chain F: 4 helices, 0 β-strands

Element	Residues	Length
α-helix	3-24	22
α-helix	51-67	17
α-helix	72-93	22
α-helix	121-141	21

Molecules and chains

Molecule	Chains	Type	Length	Organism	UniProt
Neutralizing antibody Fab fragment, heavy chain	A, D	protein	225	Homo sapiens
Neutralizing antibody Fab fragment, light chain	B, E	protein	217	Homo sapiens
Leptin	C, F	protein	146	Homo sapiens	P41159 (AlphaFold model)

Sequence of entity 1 (A, D), FASTA

>9PUO_1 Neutralizing antibody Fab fragment, heavy chain (chains A, D)
QVQLVQSGAEVKKPGSSVKVSCKASGGTFSSYAISWVRQAPGQGLEWMGGIIPIFGTANY
AQKFQGRVTITADESTSTAYMELSSLRSEDTAVYYCARSQVPSSYYYGMDVWGQGTMVTV
SSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQ
SSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPKSC

Sequence of entity 2 (B, E), FASTA

>9PUO_2 Neutralizing antibody Fab fragment, light chain (chains B, E)
QSVLTQPPSVSGAPGQRVTISCTGGNSNIGAGYHVHWYQQLPGAAPKLLIYGDTNRPSGV
PDRFSGSQSGTSASLAITGLQADDEADYYCQSYDRSRGGWFFGGGTQLTVLGQPKAAPSV
TLFPPSSEELQANKATLVCLVSDFYPGAVTVAWKADGSPVKVGVETTKPSKQSNNKYAAS
SYLSLTPEQWKSHRSYSCRVTHEGSTVEKTVAPAECS

Sequence of entity 3 (C, F), FASTA

>9PUO_3 Leptin (chains C, F)
VPIQKVQDDTKTLIKTIVTRINDISHTQSVSSKQKVTGLDFIPGLHPILTLSKMDQTLAV
YQQILTSMPSRNVIQISNDLENLRDLLHVLAFSKSCHLPEASGLETLDSLGGVLEASGYS
TEVVALSRLQGSLQDMLWQLDLSPGC

Ligands and cofactors

ID	Name	Formula	Copies
PO4	Phosphate ion	O4 P	2

Primary citation

Leptin as a key driver for organ fibrogenesis. Sun, X.N., Chen, S., Zhao, S. et al. Sci Adv (2025) 11:eady7904-eady7904. DOI 10.1126/sciadv.ady7904 · PubMed

Other PDB entries of the same protein (UniProt P41159 (AlphaFold model), which also has an AlphaFold model), best resolution first:

1AX8 2.4 Å, Human obesity protein, leptin
8X85 3.58 Å, Structure of leptin-LepR dimer
7Z3Q 3.62 Å, Crystal structure of the human leptin:LepR-CRH2 encounter complex to 3.6 A resolution.
8X81 3.77 Å, Structure of leptin-LepR trimer with a large gap
8X80 3.88 Å, Structure of leptin-LepR trimer with a small gap
8AVE 5.62 Å, Human leptin in complex with the human LEP-R ectodomain fused to a C-terminal trimeric…
8AVF 6.45 Å, Human leptin in complex with the human LEP-R ectodomain fused to a C-terminal trimeric…
8AVO 6.84 Å, Human leptin in complex with the human LEP-R ectodomain fused to a C-terminal trimeric…
8K6Z NMR structure of human leptin

Browse structure collections

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