SAXSdb — 1t8n

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

Chymotrypsin A

OrganismNot specified

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Pancreatic trypsin inhibitor × 1 （P00974） SULFATE ION × 6 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	Pancreatic trypsin inhibitor × 1 （P00974） SULFATE ION × 2 water × 2	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 4	Pancreatic trypsin inhibitor × 2 （P00974） SULFATE ION × 8 water × 4	Consistent with protein count
4	Protein heterocomplex	Heteromer	Protein 4	Pancreatic trypsin inhibitor × 2 （P00974） SULFATE ION × 8 water × 4	Consistent with protein count
5	Protein heterocomplex	Heteromer	Protein 2	Pancreatic trypsin inhibitor × 1 （P00974） SULFATE ION × 5 water × 2	Consistent with protein count
6	Protein heterocomplex	Heteromer	Protein 2	Pancreatic trypsin inhibitor × 1 （P00974） SULFATE ION × 3 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	CTRA_BOVIN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain A； PDBConstruct 1–245； UniProt 1–245 Author chain C； PDBConstruct 1–245； UniProt 1–245

Pancreatic trypsin inhibitor

Bos taurus

UniProt P00974

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	Chymotrypsin A × 1 （P00766） SULFATE ION × 6 water × 2	Consistent with protein count
2	Protein heterocomplex	Heteromer	Protein 2	Chymotrypsin A × 1 （P00766） SULFATE ION × 2 water × 2	Consistent with protein count
3	Protein heterocomplex	Heteromer	Protein 4	Chymotrypsin A × 2 （P00766） SULFATE ION × 8 water × 4	Consistent with protein count
4	Protein heterocomplex	Heteromer	Protein 4	Chymotrypsin A × 2 （P00766） SULFATE ION × 8 water × 4	Consistent with protein count
5	Protein heterocomplex	Heteromer	Protein 2	Chymotrypsin A × 1 （P00766） SULFATE ION × 5 water × 2	Consistent with protein count
6	Protein heterocomplex	Heteromer	Protein 2	Chymotrypsin A × 1 （P00766） SULFATE ION × 3 water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	BPT1_BOVIN
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain B； PDBConstruct 1–58； UniProt 36–93 Author chain D； PDBConstruct 1–58； UniProt 36–93

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	1t8n
Deposition date deposition_date	2004-05-13
Structure title title	CRYSTAL STRUCTURE OF THE P1 THR BPTI MUTANT- BOVINE CHYMOTRYPSIN COMPLEX
Keywords keywords	;CHYMOTRYPSIN, SERINE PROTEINASE, BOVINE PANCREATIC TRYPSIN INHIBITOR, BPTI, PROTEIN-PROTEIN INTERACTION, NON-COGNATE BINDING, S1 POCKET, PRIMARY SPECIFICITY, HYDROLASE-HYDROLASE INHIBITOR COMPLEX ;; HYDROLASE/HYDROLASE INHIBITOR
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.

1t8n__assembly_1__model_1

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

Download this curve (.dat)

1t8n__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1t8n__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	19.85 Å
Rg (electron density)	18.80 Å
Total Rg	19.79 Å
Atom count	2237
Residues	297
Excluded volume	39552 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1t8n__assembly_1__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
2	1	`1t8n__assembly_2__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
3	1	`1t8n__assembly_3__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
4	1	`1t8n__assembly_4__model_1`	tetrameric （4）	Success	4.1.3-1-20251215 (887e7ef)	View Download
5	1	`1t8n__assembly_5__model_1`	dimeric （2）	Success	4.1.3-1-20251215 (887e7ef)	View Download
6	1	`1t8n__assembly_6__model_1`	dimeric （2）	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 (4)

Entity 1 Entity 1 polymer

Description description	Chymotrypsin A
Molecular weight formula_weight	25686.0 kDa
EC 编号 ec_number	3.4.21.1
Mutation mutation	K50T, M87L
Source method src_method	nat
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	A,C
Atom count atom_count	5032

CGVPAIQPVLSGLSRIVNGEEAVPGSWPWQVSLQDKTGFHFCGGSLINENWVVTAAHCGVTTSDVVVAGEFDQGSSSEKIQKLKIAKVFKNSKYNSLTINNDITLLKLSTAASFSQTVSAVCLPSASDDFAAGTTCVTTGWGLTRYTNANTPDRLQQASLPLLSNTNCKKYWGTKIKDAMICAGASGVSSCMGDSGGPLVCKKNGAWTLVGIVSWGSSTCSTSTPGVYARVTALVNWVQQTLAAN

Entity 2 Entity 2 polymer

Description description	Pancreatic trypsin inhibitor
Molecular weight formula_weight	6481.5 kDa
Source method src_method	man
Copy count entity_count	2

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	B,D

RPDFCLEPPYTGPCTARIIRYFYNAKAGLCQTFVYGGCRAKRNNFKSAEDCLRTCGGA

Source Source

Source organism organism	Bos taurus
Common name common_name	cattle
NCBI taxonomy ID ncbi_taxonomy_id	9913
Host organism host_organism	Escherichia coli BL21(DE3)

Entity 3 Entity 3 non-polymer

Description description	SULFATE ION
Molecular weight formula_weight	96.1 kDa
Source method src_method	syn
Copy count entity_count	8

Entity 4 Entity 4 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	520

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6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

Domain ID domain_id	d1t8na_
Class class	b — All beta proteins
Fold Fold fold	b.47 — Trypsin-like serine proteases
Superfamily Superfamily superfamily	b.47.1 — Trypsin-like serine proteases
Family Family family	b.47.1.2 — Eukaryotic proteases

Domain ID domain_id	d1t8nb_
Class class	g — Small proteins
Fold Fold fold	g.8 — BPTI-like
Superfamily Superfamily superfamily	g.8.1 — BPTI-like
Family Family family	g.8.1.1 — Small Kunitz-type inhibitors & BPTI-like toxins

Domain ID domain_id	d1t8nc_
Class class	b — All beta proteins
Fold Fold fold	b.47 — Trypsin-like serine proteases
Superfamily Superfamily superfamily	b.47.1 — Trypsin-like serine proteases
Family Family family	b.47.1.2 — Eukaryotic proteases

Domain ID domain_id	d1t8nd_
Class class	g — Small proteins
Fold Fold fold	g.8 — BPTI-like
Superfamily Superfamily superfamily	g.8.1 — BPTI-like
Family Family family	g.8.1.1 — Small Kunitz-type inhibitors & BPTI-like toxins

CATH v4.4 (6 domains)

Domain ID domain_id	1t8nA01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	10 — Thrombin, subunit H
Homologous superfamily homologous superfamily	10 — Trypsin-like serine proteases

Domain ID domain_id	1t8nA02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	10 — Thrombin, subunit H
Homologous superfamily homologous superfamily	10 — Trypsin-like serine proteases

Domain ID domain_id	1t8nB00
Class class	4 — Few Secondary Structures
Architecture architecture	10 — Irregular
Topology topology	410 — Factor Xa Inhibitor
Homologous superfamily homologous superfamily	10 — Pancreatic trypsin inhibitor Kunitz domain

Domain ID domain_id	1t8nC01
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	10 — Thrombin, subunit H
Homologous superfamily homologous superfamily	10 — Trypsin-like serine proteases

Domain ID domain_id	1t8nC02
Class class	2 — Mainly Beta
Architecture architecture	40 — Beta Barrel
Topology topology	10 — Thrombin, subunit H
Homologous superfamily homologous superfamily	10 — Trypsin-like serine proteases

Domain ID domain_id	1t8nD00
Class class	4 — Few Secondary Structures
Architecture architecture	10 — Irregular
Topology topology	410 — Factor Xa Inhibitor
Homologous superfamily homologous superfamily	10 — Pancreatic trypsin inhibitor Kunitz domain

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7. Citations (7)

Crystal structures of five bovine chymotrypsin complexes with P1 BPTI variants.

J.Mol.Biol. (2004)

PMID: 15544809 · DOI: 10.1016/j.jmb.2004.09.088 PRIMARY

;STRUCTURAL CONSEQUENCES OF ACCOMMODATION OF FOUR NON-COGNATE AMINO-ACID RESIDUES IN THE S1 POCKET OF BOVINE TRYPSIN AND CHYMOTRYPSIN ;

J.Mol.Biol. (2003)

DOI: 10.1016/j.jmb.2003.08.059

ULTRAHIGH-RESOLUTION STRUCTURE OF A BPTI MUTANT

Acta Crystallogr.,Sect.D (2001)

DOI: 10.1107/S0907444901003468

;Crystal structures of bovine chymotrypsin and trypsin complexed to the inhibitor domain of Alzheimer's amyloid beta-protein precursor (APPI) and basic pancreatic trypsin inhibitor (BPTI): engineering of inhibitors with altered specificities ;

Protein Sci. (1997)

;Crystal structure of the bovine alpha-chymotrypsin:Kunitz inhibitor complex. An example of multiple protein:protein recognition sites. ;

J.Mol.Recog. (1997)

DOI: 10.1002/(SICI)1099-1352(199701/02)10:1<26::AID-JMR351>3.0.CO;2-N

CRYSTALLOGRAPHIC REFINEMENT OF THE STRUCTURE OF BOVINE PANCREATIC TRYPSIN INHIBITOR AT 1.5 A RESOLUTION

Acta Crystallogr.,Sect.B (1975)

DOI: 10.1107/S0567740875002415

Three-dimensional structure of tosyl-alpha-chymotrypsin

Nature (1967)

Unit-cell length a length_a	99.960 Å
Unit-cell length b length_b	99.960 Å
Unit-cell length c length_c	205.360 Å
Unit-cell angle α angle_alpha	90.00 °
Unit-cell angle β angle_beta	90.00 °
Unit-cell angle γ angle_gamma	120.00 °
Molecules per unit cell Z z_pdb	12

Space group space_group	P 61
Space-group number int_tables_number	169
Crystal system crystal_system	—

Resolution resolution	1.750 Å
Low-resolution limit resolution_low	14.980 Å
R factor r_factor	0.2000
R_work r_work	0.2000
R_free r_free	0.2140

CRYSTAL STRUCTURE OF THE P1 THR BPTI MUTANT- BOVINE CHYMOTRYPSIN COMPLEX

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

Chymotrypsin A

State in the Current Structure

Other States of the Same Protein in the Database

Pancreatic trypsin inhibitor

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

1t8n__assembly_1__model_1

1t8n__assembly_1__model_1 | I(q)

1t8n__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

CATH v4.4 (6 domains)

7. Citations (7)

CRYSTAL STRUCTURE OF THE P1 THR BPTI MUTANT- BOVINE CHYMOTRYPSIN COMPLEX

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

Chymotrypsin A

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

Pancreatic trypsin inhibitor

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

1t8n__assembly_1__model_1

1t8n__assembly_1__model_1 | I(q)

1t8n__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 (4)

Entity 1 Entity 1 polymer

Polymer Polymer

Entity 2 Entity 2 polymer

Polymer Polymer

Source Source

Entity 3 Entity 3 non-polymer

Entity 4 Entity 4 water

6. Fold Classification (SCOP + CATH) 10 domains

SCOP 2.08 (4 domains)

CATH v4.4 (6 domains)

7. Citations (7)