LNV-LAO L-amino acid oxidase (LAO)

Basic info

Binding Target: FAD, Flavoprotein

Source: Venom base

Sequence: ADDKNPLEEAFREADYEVFLEIAKNGL

Sequence Length: 27

L/D/Mix: L

L (left-handed), D (right-handed), Mix (amino acids contain both L- and D-amino acids)

Presence of non-natural amino acid: No

Linear/Cyclic: Linear

Function

LNV-LAO L-amino acid oxidase (LAO) from the leaf-nosed viper (Eristocophis macmahoni) snake venom. The induction of apoptosis by LNV-LAO was further confirmed by the DNA fragmentation assay with LAO-treated MM6 cells.In contrast, LNV whole venom nonselectively inhibits platelet aggregation induced by adenosine diphosphate, platelet activating factor and arachidonic acid (IC50 10, 8, and 6 mg/ml, respectively) mainly because of the presence of potent short-peptidyl (IC50 < 35 ng/ml) inhibitors of platelet aggregation.

Literature

Isolation, Structural, and Functional Characterization of an Apoptosis-Inducing L-Amino Acid Oxidase from Leaf-Nosed Viper (Eristocophis macmahoni) Snake Venom

DOI: 10.1006/abbi.2000.2130

Authors: Syed Abid Ali, Stanka Stoeva, Atiya Abbasi, Junaid M. Alam, Rakez Kayed, Marion Faigle, Birgid Neumeister, Wolfgang Voelter

(2000) Archives of Biochemistry and Biophysics

Abstract: The enzyme L-amino acid oxidase (LAO) from the leaf-nosed viper (Eristocophis macmahoni) snake venom was purified to homogeneity in a single step using high performance liquid chromatography on a Nucleosil 7C18 reverse phase column. The molecular mass of the purified enzyme was 58734.0 Da, as determined by matrix-assisted laser desorption/ionization mass spectrometry. The N-terminal amino acid sequence (ADDKNPLEEAFREADYEVFLEIAKNGL) and the chemical composition of the purified LNV-LAO shows close structural homology with other L-amino acid oxidases isolated from different snake venoms. The secondary structural contents analysis of LAO, established by means of circular dichroism, revealed ca. 49% alpha-helix, 19% beta-sheet, 10% beta-turn, and 22% random coil structure. The purified LNV-LAO not only retained its specific enzymatic activity (73.46 U/mg), determined against L-leucine as a substrate, but also exhibited potent haemolytic (1-10 microg/ml), edema- (MED 4.8 microg/ml) and human platelet aggregation-inducing (ED50 33 microg/ml) properties. Unlike other haemorrhagic snake venom L-amino acid oxidases, the LNV-LAO does not produce haemorrhage. In addition to these local effects, the purified LNV-LAO showed apoptosis-inducing activity in the MM6 cell culture assay. After 18 h treatment with 25-100 microg/ml of LAO, the typical DNA fragmentation pattern of apoptotic cells was observed by means of fluorescent microscopy and agarose gel electrophoresis.

Experimental Data

Secondary structure prediction

Secondary structure prediction is reported in ApInAPDB using Chou-Fasman, GOR, Neural Network algorithms (cib.cf.ocha.ac.jp/bitool/MIX/ ) (ver. 1.1) available on Center for Information Biology (CIB) created by Ochanomizu University. In addition, CIB provides users with the facility to reach a consensus on the secondary structure prediction based on the three aforementioned algorithms. Therefore, a consentaneous result

Predict locations of peptide secondary structures from amino acid sequence based on "majority is right" method using CF, GOR, and NN.

is reported for each peptide.

H=Helix, E=Extended strand, C=Coil, T=Turn
Method	Structure
Chou-Fasman	CCCCHHHHHHHHHHHCHHHHHHHCCCC
GOR	CTTTCCHHHHHHHHHHHHHHHHHHTTC
Neural Network	CCCCCCCCHHHHHHHHHHHHHHHHCCC
Consentaneous Result Predict locations of peptide secondary structures from amino acid sequence based on "majority is right" method using CF, GOR, and NN.	CCCCCCHHHHHHHHHHHHHHHHHHCCC

Local Structure prediction profile

Using PEP-FOLL3 server (bioserv.rpbs.univ-paris-diderot.fr/services/PEP-FOLD3/) both Local Structure prediction profile and downloadable PDB structure file are developed.

It corresponds to a graphical representation of the probabilities of each Structural Alphabet (SA) - letter (vertical axis) at each position of the sequence (horizontal axis).
Note that SA letters correspond to fragments of 4 residue length. The profile is presented using the following color code: red: helical, green: extended, blue: coil.

Physicochemical properties

Net Charge at pH 7: -4.99

Charge: -5

Charge= Na + Nb (Na: Number of acidic amino acid residues, Nb: Number of basic amino acid residues) Each acidic amino acid residues are assigned a value of -1, basic amino acid residues are assigned a value of 1 and neutral amino acid residues are assigned a value of 0.

Isoelectric Point: 3.71

Hydrophobicity at pH 2.0: 24.37

Hydrophobicity at pH 2.0 (Hydrophobicity value at pH 2= Hydrophobicity value of individual amino acid at pH 2 / Total number of amino acid in the peptide)

Hydrophobicity at pH 6.8: 14.37

Hydrophobicity at pH 6.8 (Hydrophobicity value at pH 6.8= Hydrophobicity value of individual amino acid at pH 6.8 / Total number of amino acid in the peptide)

GRAVY: -0.66

The GRAVY value for a peptide is calculated as the sum of hydropathy values of all the amino acids, divided by the number of residues in the sequence. positive GRAVY (hydrophobic), negative GRAVY (hydrophilic).

Molecular Weight (g/mol): 3097.51

Descriptors for QSAR modeling

To help scientists in QSAR modeling development, 1559 descriptors are calculated for each peptide using BioProt available in Biotriangle web server (http://biotriangle.scbdd.com/protein/index/ ) and presented as downloadable CSV file format.

Description presented in BioTriangle web server for descriptors calculated by BioProt

3D view