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91  structures 150  species 0  interactions 2696  sequences 33  architectures

Family: Tryp_alpha_amyl (PF00234)

Summary: Protease inhibitor/seed storage/LTP family

Pfam includes annotations and additional family information from a range of different sources. These sources can be accessed via the tabs below.

This is the Wikipedia entry entitled "Plant lipid transfer proteins". More...

Plant lipid transfer proteins Edit Wikipedia article

Plant lipid transfer protein
Surface 1UVB.png
Oryza sativa Lipid Transfer Protein 1 bound to Palmitic acid (black). Positive charge in blue, negative charge in red. (PDB:1UVB [1])

Plant lipid transfer proteins, also known as plant LTPs or PLTPs, are a group of highly-conserved proteins of about 7-9kDa found in higher plant tissues.[1][2] As its name implies, lipid transfer proteins are responsible for the shuttling of phospholipids and other fatty acid groups between cell membranes.[3] LTPs are divided into two structurallyrelated subfamilies according to their molecular masses: LTP1s (9 kDa) and LTP2s (7 kDa).[4] Various LTPs bind a wide range of ligands, including fatty acids (FAs) with a C10–C18 chain length, acyl derivatives of coenzyme A (CoA), phospho- and galactolipids, prostaglandin B2, sterols, molecules of organic solvents, and some drugs.[2] LTP2

Biological activity

LTPs constitute one of the classes of defense PRPs, many of which have antimicrobial and enzymatic activities or are enzyme inhibitors. Different proteins of this class can exhibit the following activities:[2]

  • antibacterial
  • antifungal
  • antiviral
  • antiproliferative

and inhibit some enzymes.


Ordinarily, most lipids do not spontaneously exit membranes because their hydrophobicity makes them poorly soluble in water. LTPs facilitate the movement of lipids between membranes by binding, and solubilising them. LTPs typically have broad substrate specificity and so can interact with a variety of different lipids.[5]

LTPs in plants may be involved in:

  • cutin biosynthesis
  • surface wax formation
  • mitochondrial growth
  • pathogen defense reactions
  • adaptation to environmental changes[6]
  • lipid metabolism
  • fertilization of flowering plants
  • adaptation of plants under stress conditions
  • activation and regulation of signaling cascades
  • apoptosis
  • symbiosis
  • fruit ripening[2]


Structure of OsLTP1 (white) bound to Palmitic acid (black). Disulphides indicated in yellow.
Surface charge distribution. Positive charge in blue, negative charge in red.
Cut-through showing internal charge distribution. Positive charge in blue, negative charge in red.
Oryza sativa Lipid Transfer Protein 1 bound to Palmitic acid. (PDB: 1UVB​)

Plant lipid transfer proteins consist of 4 alpha-helices in a right-handed superhelix with a folded leaf topology. The structure is stabilised by disulfide bonds linking the helices to each other.

The structure forms an internal hydrophobic cavity in which 1-2 lipids can be bound. The outer surface of the protein is hydrophilic allowing the complex to be soluble. The use of hydrophobic interactions, with very few charged interactions, allows the protein to have broad specificity for a range of lipids.[5]

Other related proteins

Plant lipid transfer proteins share the same structural domain[7] with seed storage proteins[8] and trypsin-alpha amylase inhibitors.[9][10] These proteins share the same superhelical, disulphide-stabilised four-helix bundle containing an internal cavity.

There is no sequence similarity between animal and plant LTPs. In animals, cholesterylester transfer protein (CETP), also called plasma lipid transfer protein, is a plasma protein that facilitates the transport of cholesteryl esters and triglycerides between the lipoproteins.

Role in human health

PLTPs are pan-allergens, [11] [12] and may be directly responsible for cases of food allergy. Pru p 3, the major allergen from peach, is a 9-kDa allergen belonging to the family of lipid-transfer proteins. [13] Allergic properties are closely linked with high thermal stability and resistance to gastrointestinal proteolysis of the proteins.[14] Many of the LTP allergens are able to cause not only manifestation of allergic reactions but also sensitization via the gastrointestinal tract, being thus class I food allergens.[4] In contrast, class II food allergens are able only to elicit allergic symptoms due to its cross-reactivity with major sensitizer.

They are used as antioxidants and prevent diseases.[15]

Commercial importance

Lipid transfer protein 1 (from barley) is responsible, when denatured by the mashing process, for the bulk of foam which forms on top of beer.[16]

See also


  1. ^ Asero R, Mistrello G, Roncarolo D, de Vries SC, Gautier MF, Ciurana CL, Verbeek E, Mohammadi T, Knul-Brettlova V, Akkerdaas JH, Bulder I, Aalberse RC, van Ree R (2001). "Lipid transfer protein: a pan-allergen in plant-derived foods that is highly resistant to pepsin digestion". International Archives of Allergy and Immunology. 124 (1–3): 67–9. doi:10.1159/000053671. PMID 11306929.
  2. ^ a b c d Finkina EI, Melnikova DN, Bogdanov IV, Ovchinnikova TV (2016). "Lipid Transfer Proteins As Components of the Plant Innate Immune System: Structure, Functions, and Applications". Acta Naturae. 8 (2): 47–61. doi:10.32607/20758251-2016-8-2-47-61. PMC 4947988. PMID 27437139.
  3. ^ Kader JC (June 1996). "Lipid-Transfer Protein in Plants". Annual Review of Plant Physiology and Plant Molecular Biology. 47: 627–654. doi:10.1146/annurev.arplant.47.1.627. PMID 15012303.
  4. ^ a b Finkina EI, Melnikova DN, Bogdanov IV, Ovchinnikova TV (2017-07-04). "Plant Pathogenesis-Related Proteins PR-10 and PR-14 as Components of Innate Immunity System and Ubiquitous Allergens". Current Medicinal Chemistry. 24 (17): 1772–1787. doi:10.2174/0929867323666161026154111. PMID 27784212.
  5. ^ a b Cheng HC, Cheng PT, Peng P, Lyu PC, Sun YJ (September 2004). "Lipid binding in rice nonspecific lipid transfer protein-1 complexes from Oryza sativa". Protein Science. 13 (9): 2304–15. doi:10.1110/ps.04799704. PMC 2280015. PMID 15295114.
  6. ^ Kader, Jean-Claude (February 1997). "Science Direct". Trends in Plant Science. 2 (2): 66–70. doi:10.1016/S1360-1385(97)82565-4.
  7. ^ Lin KF, Liu YN, Hsu ST, Samuel D, Cheng CS, Bonvin AM, Lyu PC (April 2005). "Characterization and structural analyses of nonspecific lipid transfer protein 1 from mung bean". Biochemistry. 44 (15): 5703–12. doi:10.1021/bi047608v. PMID 15823028.
  8. ^ Pantoja-Uceda D, Bruix M, Giménez-Gallego G, Rico M, Santoro J (December 2003). "Solution structure of RicC3, a 2S albumin storage protein from Ricinus communis". Biochemistry. 42 (47): 13839–47. doi:10.1021/bi0352217. PMID 14636051.
  9. ^ Oda Y, Matsunaga T, Fukuyama K, Miyazaki T, Morimoto T (November 1997). "Tertiary and quaternary structures of 0.19 alpha-amylase inhibitor from wheat kernel determined by X-ray analysis at 2.06 A resolution". Biochemistry. 36 (44): 13503–11. doi:10.1021/bi971307m. PMID 9354618.
  10. ^ Gourinath S, Alam N, Srinivasan A, Betzel C, Singh TP (March 2000). "Structure of the bifunctional inhibitor of trypsin and alpha-amylase from ragi seeds at 2.2 A resolution". Acta Crystallographica D. 56 (Pt 3): 287–93. doi:10.1107/s0907444999016601. PMID 10713515.
  11. ^ Morris A. "Food Allergy in Detail". Surrey Allergy Clinic.
  12. ^ InterProIPR000528
  13. ^ Besler M, Herranz JC, Fernández-Rivas M (2000). "Peach allergy". Internet Symposium on Food Allergens. 2 (4): 185–201.
  14. ^ Bogdanov IV, Shenkarev ZO, Finkina EI, Melnikova DN, Rumynskiy EI, Arseniev AS, Ovchinnikova TV (April 2016). "A novel lipid transfer protein from the pea Pisum sativum: isolation, recombinant expression, solution structure, antifungal activity, lipid binding, and allergenic properties". BMC Plant Biology. 16: 107. doi:10.1186/s12870-016-0792-6. PMC 4852415. PMID 27137920.
  15. ^ Halliwell B (1996). "Antioxidants in human health and disease". Annual Review of Nutrition. 16: 33–50. doi:10.1146/ PMID 8839918.
  16. ^ "Foam". Carlsberg Research Laboratory.

This page is based on a Wikipedia article. The text is available under the Creative Commons Attribution/Share-Alike License.

This tab holds the annotation information that is stored in the Pfam database. As we move to using Wikipedia as our main source of annotation, the contents of this tab will be gradually replaced by the Wikipedia tab.

Protease inhibitor/seed storage/LTP family Provide feedback

This family is composed of trypsin-alpha amylase inhibitors, seed storage proteins and lipid transfer proteins from plants.

Literature references

  1. Rico M, Bruix M, Gonzalez C, Monsalve RI, Rodriguez R; , Biochemistry 1996;35:15672-15682.: 1H NMR assignment and global fold of napin BnIb, a representative 2S albumin seed protein. PUBMED:8961930 EPMC:8961930

Internal database links

External database links

This tab holds annotation information from the InterPro database.

InterPro entry IPR016140

This entry represents a structural domain consisting of 4-helices with a folded leaf topology, and forming a right-handed superhelix. This domain occurs in several proteins, including:

  • Plant lipid-transfer proteins, such as the non-specific lipid-transfer proteins ns-LTP1 and ns-LTP2 [ PUBMED:10491104 , PUBMED:12011089 ].
  • Proteinase/alpha-amylase inhibitors, such as trypsin/alpha-amylase inhibitor RBI from Eleusine coracana (Indian finger millet) [ PUBMED:9687373 ] and Hageman factor/amylase inhibitor from Zea mays (Maize) [ PUBMED:9799488 ].
  • Seed storage proteins, such as napin from Brassica napus (Rape) [ PUBMED:8961930 ] and 2S albumin from Ricinus communis (Castor bean) [ PUBMED:14636051 ].

Domain organisation

Below is a listing of the unique domain organisations or architectures in which this domain is found. More...

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Pfam Clan

This family is a member of clan Prolamin (CL0482), which has the following description:

This superfamily is characterised by families with only slightly differing disulfide-bonding patterning.

The clan contains the following 5 members:

Gliadin Hydrophob_seed LTP_2 Prolamin_like Tryp_alpha_amyl


We store a range of different sequence alignments for families. As well as the seed alignment from which the family is built, we provide the full alignment, generated by searching the sequence database (reference proteomes) using the family HMM. We also generate alignments using four representative proteomes (RP) sets and the UniProtKB sequence database. More...

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Representative proteomes UniProt

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You can also download a FASTA format file containing the full-length sequences for all sequences in the full alignment.

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HMM logos is one way of visualising profile HMMs. Logos provide a quick overview of the properties of an HMM in a graphical form. You can see a more detailed description of HMM logos and find out how you can interpret them here. More...


This page displays the phylogenetic tree for this family's seed alignment. We use FastTree to calculate neighbour join trees with a local bootstrap based on 100 resamples (shown next to the tree nodes). FastTree calculates approximately-maximum-likelihood phylogenetic trees from our seed alignment.

Note: You can also download the data file for the tree.

Curation and family details

This section shows the detailed information about the Pfam family. You can see the definitions of many of the terms in this section in the glossary and a fuller explanation of the scoring system that we use in the scores section of the help pages.

Curation View help on the curation process

Seed source: Prosite
Previous IDs: tryp_alpha_amyl;
Type: Domain
Sequence Ontology: SO:0000417
Author: Bateman A , Finn RD , Griffiths-Jones SR
Number in seed: 183
Number in full: 2696
Average length of the domain: 94.60 aa
Average identity of full alignment: 25 %
Average coverage of the sequence by the domain: 67.49 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 61295632 -E 1000 --cpu 4 HMM pfamseq
Model details:
Parameter Sequence Domain
Gathering cut-off 21.7 21.7
Trusted cut-off 21.7 21.7
Noise cut-off 21.6 21.6
Model length: 87
Family (HMM) version: 25
Download: download the raw HMM for this family

Species distribution

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For those sequences which have a structure in the Protein DataBank, we use the mapping between UniProt, PDB and Pfam coordinate systems from the PDBe group, to allow us to map Pfam domains onto UniProt sequences and three-dimensional protein structures. The table below shows the structures on which the Tryp_alpha_amyl domain has been found. There are 91 instances of this domain found in the PDB. Note that there may be multiple copies of the domain in a single PDB structure, since many structures contain multiple copies of the same protein sequence.

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AlphaFold Structure Predictions

The list of proteins below match this family and have AlphaFold predicted structures. Click on the protein accession to view the predicted structure.

Protein Predicted structure External Information
A0A0P0WNP9 View 3D Structure Click here
A0A0P0WT47 View 3D Structure Click here
A0A0P0X3X4 View 3D Structure Click here
A0A0R0LIM3 View 3D Structure Click here
A0A1D6F5A7 View 3D Structure Click here
A0A1D6J1A0 View 3D Structure Click here
A0A1D6JKW8 View 3D Structure Click here
A0A1D6NQP9 View 3D Structure Click here
A0A1D6NQQ1 View 3D Structure Click here
B6SMH0 View 3D Structure Click here
C6SVW1 View 3D Structure Click here
C6SWY4 View 3D Structure Click here
C6SXT1 View 3D Structure Click here
C6TFC1 View 3D Structure Click here
C6TFP9 View 3D Structure Click here
C7J9I2 View 3D Structure Click here
F4HZB9 View 3D Structure Click here
F4JL89 View 3D Structure Click here
I1J7M1 View 3D Structure Click here
I1J7P1 View 3D Structure Click here
I1JL08 View 3D Structure Click here
I1JL10 View 3D Structure Click here
I1KTU5 View 3D Structure Click here
I1L715 View 3D Structure Click here
I1L740 View 3D Structure Click here
I1MJG4 View 3D Structure Click here
I1N393 View 3D Structure Click here
I1N394 View 3D Structure Click here
K7K3K2 View 3D Structure Click here
K7KCN6 View 3D Structure Click here
K7W991 View 3D Structure Click here
O64864 View 3D Structure Click here
O65091 View 3D Structure Click here
O65369 View 3D Structure Click here
P01088 View 3D Structure Click here
P08031 View 3D Structure Click here
P15457 View 3D Structure Click here
P15458 View 3D Structure Click here
P15459 View 3D Structure Click here
P15460 View 3D Structure Click here