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72  structures 57  species 3  interactions 1164  sequences 11  architectures

Family: Tryp_alpha_amyl (PF00234)

Summary: Protease inhibitor/seed storage/LTP family

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

Plant lipid transfer proteins Edit Wikipedia article

Plant lipid transfer protein/seed storage/trypsin-alpha amylase inhibitor
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])
Symbol LTP/seed_store/tryp_amyl_inhib
Pfam PF00234
InterPro IPR003612

Plant lipid transfer proteins, also known as plant LTPs or PLTPs, are a group of highly-conserved proteins of about 9kDa found in higher plant tissues.[1] As its name implies, lipid transfer proteins are responsible for the shuttling of phospholipids and other fatty acid groups between cell membranes.[2] LTPs are also able to bind acyl groups.[2]


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.[3]

LTPs in plants may be involved in:

  • cutin biosynthesis
  • surface wax formation
  • mitochondrial growth
  • pathogen defense reactions
  • adaptation to environmental changes[4]


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.[3]

Other related proteins

Plant lipid transfer proteins share the same structural domain[5] with seed storage proteins[6] and trypsin-alpha amylase inhibitors.[7][8] 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, [9] [10] 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. [11]

They are used as antioxidants and prevent diseases.[citation needed]

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.[12]

See also


  1. ^
  2. ^ a b
  3. ^ 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. PMC 2280015Freely accessible. PMID 15295114. doi:10.1110/ps.04799704. 
  4. ^ "Science Direct". Trends in Plant Science. 2: 66–70. doi:10.1016/S1360-1385(97)82565-4. 
  5. ^ Bonvin AM, Lyu PC, Samuel D, Cheng CS, Lin KF, Liu YN, Hsu ST (2005). "Characterization and structural analyses of nonspecific lipid transfer protein 1 from mung bean". Biochemistry. 44 (15): 5703–12. PMID 15823028. doi:10.1021/bi047608v. 
  6. ^ Bruix M, Santoro J, Rico M, Gimenez-Gallego G, Pantoja-Uceda D (2003). "Solution structure of RicC3, a 2S albumin storage protein from Ricinus communis". Biochemistry. 42 (47): 13839–47. PMID 14636051. doi:10.1021/bi0352217. 
  7. ^ Fukuyama K, Oda Y, Morimoto T, Matsunaga T, Miyazaki T (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. PMID 9354618. doi:10.1021/bi971307m. 
  8. ^ Betzel C, Srinivasan A, Singh TP, Gourinath S, Alam N (2000). "Structure of the bifunctional inhibitor of trypsin and alpha-amylase from ragi seeds at 2.2 A resolution". Acta Crystallogr. D. 56 (Pt 3): 287–93. PMID 10713515. doi:10.1107/s0907444999016601. 
  9. ^
  10. ^
  11. ^ Peach allergy, M.Besler et al.
  12. ^

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:

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, the UniProtKB sequence database, the NCBI sequence database, and our metagenomics sequence database. More...

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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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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.

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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: Family
Author: Bateman A, Finn RD, Griffiths-Jones SR
Number in seed: 183
Number in full: 1164
Average length of the domain: 93.60 aa
Average identity of full alignment: 25 %
Average coverage of the sequence by the domain: 69.50 %

HMM information View help on HMM parameters

HMM build commands:
build method: hmmbuild -o /dev/null HMM SEED
search method: hmmsearch -Z 26740544 -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: 21
Download: download the raw HMM for this family

Species distribution

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Archea Archea Eukaryota Eukaryota
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There are 3 interactions for this family. More...

SBP_bac_1 Tryp_alpha_amyl Alpha-amylase


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 72 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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