8aci

Structure of ARG-117 Fab in complex with a fragment of complement C2, neutral pH

Method: X-RAY DIFFRACTION

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1. Protein Identity and Related Structures Protein Identity & Related Structures

Complement C2b fragment

Homo sapiens

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Other combination	Heteromer	Protein 4 其他Polymer 1	ARGX-117 Fab heavy chain × 1 nanobody specific for kappa light chain of Fab × 1 ARGX-117 Fab light chain × 1 alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranose × 1 CALCIUM ION × 1 CHLORIDE ION × 1 (4S)-2-METHYL-2,4-PENTANEDIOL × 1 water × 4	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CO2_HUMAN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–197； UniProt 21–217

The page prioritizes protein identity, the current assembly, associated components, oligomeric state and cross-PDB links. Chain mapping and sequence ranges are retained as data evidence. Internal IDs, import timestamps and assembly operation expressions are maintenance fields and are not shown here.

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2. Structure Basics 2. Structure Basics

Entry ID entry_id	8aci
Deposition date deposition_date	2022-07-05
Structure title title	Structure of ARG-117 Fab in complex with a fragment of complement C2, neutral pH
Keywords keywords	innate immune system, antibody, complement, IMMUNE SYSTEM; IMMUNE SYSTEM
Experimental Method method	X-RAY DIFFRACTION

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3. Official assembly/model SAXS Official SAXS Profiles

This page reads only the latest assembly calculations. Every curve maps to an explicit PDB entry, official biological assembly and coordinate model.

8aci__assembly_1__model_1

Assembly 1 · Model 1 · CRYSOL 4.1.3-1-20251215 (887e7ef)

Download this curve (.dat)

8aci__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

8aci__assembly_1__model_1 | P(r) · Pending

P(r) will be calculated and displayed separately for the same assembly/model.

Rg（Guinier）	32.51 Å
Rg (electron density)	31.94 Å
Total Rg	32.44 Å
Atom count	10456
Residues	700
Excluded volume	94241 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`8aci__assembly_1__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download

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4. Crystallography and Experiment 4. Crystallography & Experiment

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5. Entities and Polymers Entities & Polymers (9)

Entity 1 Entity 1 polymer

Description description	Complement C2b fragment
Molecular weight formula_weight	20991.4 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A
Atom count atom_count	10742

APSCPQNVNISGGTFTLSHGWAPGSLLTYSCPQGLYPSPASRLCKSSGQWQTPGATRSLSKAVCKPVRCPAPVSFENGIYTPRLGSYPVGGNVSFECEDGFILRGSPVRQCRPNGMWDGETAVCDNGAGHCPNPGISLGAVRTGFRFGHGDKVRYRCSSNLVLTGSSERECQGNGVWSGTEPICRQPYSYDFPEDVA

Source Source

Source organism organism	Homo sapiens
Common name common_name	human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 2 Entity 2 polymer

Description description	ARGX-117 Fab heavy chain
Molecular weight formula_weight	23450.1 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	H

EVQLVQSGAEVKKPGASVKVSCKASGYTFTDYNMDWVRQATGQGLEWIGDINPNYESTGYNQKFKGRATMTVDKSISTAYMELSSLRSEDTAVYYCAREDDHDAFAYWGQGTLVTVSSASTKGPSVFPLAPSSKSTSGGTAALGCLVKDYFPEPVTVSWNSGALTSGVHTFPAVLQSSGLYSLSSVVTVPSSSLGTQTYICNVNHKPSNTKVDKKVEPK

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 3 Entity 3 polymer

Description description	nanobody specific for kappa light chain of Fab
Molecular weight formula_weight	14204.5 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	K

QVQLQESGGGLVQPGGSLRLSCAASGRTISRYAMSWFRQAPGKEREFVAVARRSGDGAFYADSVQGRFTVSRDDAKNTVYLQMNSLKPEDTAVYYCAIDSDTFYSGSYDYWGQGTQVTVSSEHHHHHH

Source Source

Source organism organism	Lama glama
NCBI taxonomy ID ncbi_taxonomy_id	9844
Host organism host_organism	Escherichia coli

Entity 4 Entity 4 polymer

Description description	ARGX-117 Fab light chain
Molecular weight formula_weight	23957.6 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	L

DNVLTQSPDSLAVSLGERATISCRASKSVRTSGYNYMHWYQQKPGQPPKLLIYLASNLKSGVPDRFSGSGSGTDFTLTISSLQAEDAATYYCQHSRELPYTFGQGTKLEIKRTVAAPSVFIFPPSDEQLKSGTASVVCLLNNFYPREAKVQWKVDNALQSGNSQESVTEQDSKDSTYSLSSTLTLSKADYEKHKVYACEVTHQGLSSPVTKSFNRGEC

Source Source

Source organism organism	Homo sapiens
Common name common_name	Human
NCBI taxonomy ID ncbi_taxonomy_id	9606
Host organism host_organism	Homo sapiens

Entity 5 Entity 5 branched

Description description	alpha-L-fucopyranose-(1-6)-2-acetamido-2-deoxy-beta-D-glucopyranose
Molecular weight formula_weight	367.3 kDa
Source method src_method	man
Copy count entity_count	1

Entity 6 Entity 6 non-polymer

Description description	CALCIUM ION
Molecular weight formula_weight	40.1 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 7 Entity 7 non-polymer

Description description	CHLORIDE ION
Molecular weight formula_weight	35.5 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 8 Entity 8 non-polymer

Description description	(4S)-2-METHYL-2,4-PENTANEDIOL
Molecular weight formula_weight	118.2 kDa
Source method src_method	syn
Copy count entity_count	1

Entity 9 Entity 9 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	285

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Unit-cell length a length_a	71.590 Å
Unit-cell length b length_b	88.760 Å
Unit-cell length c length_c	144.780 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	90.00 °
Molecules per unit cell Z z_pdb	4

Space group space_group	P 21 21 21
Space-group number int_tables_number	19
Crystal system crystal_system	orthorhombic

Resolution resolution	1.850 Å
Low-resolution limit resolution_low	44.160 Å
R factor r_factor	0.1877
R_work r_work	0.1871
R_free r_free	0.1994

Structure of ARG-117 Fab in complex with a fragment of complement C2, neutral pH

1. Protein Identity and Related Structures Protein Identity & Related Structures

Complement C2b fragment

State in the Current Structure

Other States of the Same Protein in the Database

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

8aci__assembly_1__model_1

8aci__assembly_1__model_1 | I(q)

8aci__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (9)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 branched

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 water

7. Citations (1)

Structure of ARG-117 Fab in complex with a fragment of complement C2, neutral pH

1. Protein Identity and Related Structures Protein Identity & Related Structures

Complement C2b fragment

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

2. Structure Basics 2. Structure Basics

3. Official assembly/model SAXS Official SAXS Profiles

8aci__assembly_1__model_1

8aci__assembly_1__model_1 | I(q)

8aci__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

Diffraction experiment Diffraction

5. Entities and Polymers Entities & Polymers (9)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 polymer

Polymer Polymer

Source Source

Entity 4 Entity 4 polymer

Polymer Polymer

Source Source

Entity 5 Entity 5 branched

Entity 6 Entity 6 non-polymer

Entity 7 Entity 7 non-polymer

Entity 8 Entity 8 non-polymer

Entity 9 Entity 9 water

7. Citations (1)