SAXSdb — 1ppe

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

TRYPSIN

Bos taurus

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	TRYPSIN INHIBITOR CMTI-I × 1 （P01074） water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	TRY1_BOVIN
Isoform	—
PDB entities	1
Chains and sequence ranges	Author chain E； PDBConstruct 1–223； UniProt 21–243

TRYPSIN INHIBITOR CMTI-I

OrganismNot specified

UniProt P01074

State in the Current Structure

Assembly	Physical composition	Protein state	Molecular copy count	Associated components	Data consistency
1	Protein heterocomplex	Heteromer	Protein 2	TRYPSIN × 1 （P00760） water × 2	Consistent with protein count

Other States of the Same Protein in the Database

View Construct and Data Evidence

UniProt name	ITR1_CUCMA
Isoform	—
PDB entities	2
Chains and sequence ranges	Author chain I； PDBConstruct 1–29； UniProt 1–29

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	1ppe
Deposition date deposition_date	1991-10-24
Structure title title	THE REFINED 2.0 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF THE COMPLEX FORMED BETWEEN BOVINE BETA-TRYPSIN AND CMTI-I, A TRYPSIN INHIBITOR FROM SQUASH SEEDS (CUCURBITA MAXIMA): TOPOLOGICAL SIMILARITY OF THE SQUASH SEED INHIBITORS WITH THE CARBOXYPEPTIDASE A INHIBITOR FROM POTATOES
Keywords keywords	SERINE PROTEINASE, 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.

1ppe__assembly_1__model_1

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

Download this curve (.dat)

1ppe__assembly_1__model_1 | I(q)

100 plotted points; both axes use logarithmic scales.

1ppe__assembly_1__model_1 | P(r) · Pending

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

Rg（Guinier）	17.64 Å
Rg (electron density)	16.52 Å
Total Rg	17.53 Å
Atom count	1851
Residues	252
Excluded volume	32795 Å³
Maximum q	0.500 Å⁻¹

Assembly	Model	Structure unit	Oligomeric description	Status	CRYSOL	Actions
1	1	`1ppe__assembly_1__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 (3)

Entity 1 Entity 1 polymer

Description description	TRYPSIN
Molecular weight formula_weight	23324.3 kDa
EC 编号 ec_number	3.4.21.4
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	E
Atom count atom_count	1991

IVGGYTCGANTVPYQVSLNSGYHFCGGSLINSQWVVSAAHCYKSGIQVRLGEDNINVVEGNEQFISASKSIVHPSYNSNTLNNDIMLIKLKSAASLNSRVASISLPTSCASAGTQCLISGWGNTKSSGTSYPDVLKCLKAPILSDSSCKSAYPGQITSNMFCAGYLEGGKDSCQGDSGGPVVCSGKLQGIVSWGSGCAQKNKPGVYTKVCNYVSWIKQTIASN

Source Source

Source organism organism	Bos taurus
Common name common_name	cattle
NCBI taxonomy ID ncbi_taxonomy_id	9913

Entity 2 Entity 2 polymer

Description description	TRYPSIN INHIBITOR CMTI-I
Molecular weight formula_weight	3279.9 kDa
Source method src_method	man
Copy count entity_count	1

Polymer Polymer

Polymer type type	polypeptide(L)
Chain IDs strand_id	I

RVCPRILMECKKDSDCLAECVCLEHGYCG

Entity 3 Entity 3 water

Description description	water
Molecular weight formula_weight	18.0 kDa
Source method src_method	nat
Copy count entity_count	140

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6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

Domain ID domain_id	d1ppee_
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	d1ppei_
Class class	g — Small proteins
Fold Fold fold	g.3 — Knottins (small inhibitors, toxins, lectins)
Superfamily Superfamily superfamily	g.3.2 — Plant inhibitors of proteinases and amylases
Family Family family	g.3.2.1 — Plant inhibitors of proteinases and amylases

CATH v4.4 (2 domains)

Domain ID domain_id	1ppeE01
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	1ppeE02
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

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7. Citations (6)

;The refined 2.0 A X-ray crystal structure of the complex formed between bovine beta-trypsin and CMTI-I, a trypsin inhibitor from squash seeds (Cucurbita maxima). Topological similarity of the squash seed inhibitors with the carboxypeptidase A inhibitor from potatoes ;

FEBS Lett. (1989)

PMID: 2914611 · DOI: 10.1016/0014-5793(89)80486-7 PRIMARY

Ligand Binding: Proteinase-Protein Inhibitor Interactions

Curr.Opin.Struct.Biol. (1991)

;Nuclear Magnetic Resonance Solution and X-Ray Structures of Squash Trypsin Inhibitor Exhibit the Same Conformation of the Proteinase Binding Loop ;

J.Mol.Biol. (1989)

;The Squash Family of Serine Proteinase Inhibitors. Amino Acid Sequences and Association Equilibrium Constants of Inhibitors from Squash, Summer Squash, Zucchini, and Cucumber Seeds ;

Biochem.Biophys.Res.Commun. (1985)

Amino-Acid Sequence of Two Trypsin Isoinhibitors, Itd I and Itd III from Squash Seeds (Cucurbita Maxima)

;Hoppe-Seyler's Z.Physiol.Chem. ; (1983)

;The Refined Crystal Structure of Bovine Beta-Trypsin at 1.8 Angstroms Resolution. Crystallographic Refinement, Calcium Binding Site, Benzamidine Binding Site and Active Site at Ph 7.0 ;

J.Mol.Biol. (1975)

Unit-cell length a length_a	59.280 Å
Unit-cell length b length_b	55.470 Å
Unit-cell length c length_c	74.590 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	—

Resolution resolution	2.000 Å
Low-resolution limit resolution_low	6.000 Å
R factor r_factor	—
R_work r_work	0.1510
R_free r_free	—

THE REFINED 2.0 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF THE COMPLEX FORMED BETWEEN BOVINE BETA-TRYPSIN AND CMTI-I, A TRYPSIN INHIBITOR FROM SQUASH SEEDS (CUCURBITA MAXIMA): TOPOLOGICAL SIMILARITY OF THE SQUASH SEED INHIBITORS WITH THE CARBOXYPEPTIDASE A INHIBITOR FROM POTATOES

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

TRYPSIN

State in the Current Structure

Other States of the Same Protein in the Database

TRYPSIN INHIBITOR CMTI-I

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

1ppe__assembly_1__model_1

1ppe__assembly_1__model_1 | I(q)

1ppe__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (6)

THE REFINED 2.0 ANGSTROMS X-RAY CRYSTAL STRUCTURE OF THE COMPLEX FORMED BETWEEN BOVINE BETA-TRYPSIN AND CMTI-I, A TRYPSIN INHIBITOR FROM SQUASH SEEDS (CUCURBITA MAXIMA): TOPOLOGICAL SIMILARITY OF THE SQUASH SEED INHIBITORS WITH THE CARBOXYPEPTIDASE A INHIBITOR FROM POTATOES

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

TRYPSIN

State in the Current Structure

Other States of the Same Protein in the Database

Monomer

Homodimer

Homotetramer

Other homooligomers

Heteromeric or nucleic-acid complex

TRYPSIN INHIBITOR CMTI-I

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

1ppe__assembly_1__model_1

1ppe__assembly_1__model_1 | I(q)

1ppe__assembly_1__model_1 | P(r) · Pending

4. Crystallography and Experiment 4. Crystallography & Experiment

Unit cell Unit Cell

Symmetry Symmetry

Refinement Refinement

5. Entities and Polymers Entities & Polymers (3)

Entity 1 Entity 1 polymer

Polymer Polymer

Source Source

Entity 2 Entity 2 polymer

Polymer Polymer

Entity 3 Entity 3 water

6. Fold Classification (SCOP + CATH) 4 domains

SCOP 2.08 (2 domains)

CATH v4.4 (2 domains)

7. Citations (6)