SASDA94: Der p21 (Der p21, allegren, Derp21)

Basic information

• Entry: Database: SASBDB / ID: SASDA94

Sample

Der p21

• Der p21, allegren (protein), Derp21, Escherichia coli

• Biological species: Escherichia coli (E. coli)
• Citation: Journal: Allergy / Year: 2008; Title: Characterization of Der p 21, a new important allergen derived from the gut of house dust mites.; Authors: M Weghofer / Y Dall'Antonia / M Grote / A Stöcklinger / M Kneidinger / N Balic / M-T Krauth / E Fernández-Caldas / W R Thomas / M van Hage / S Vieths / S Spitzauer / F Horak / D I Svergun / P V Konarev / P Valent / J Thalhamer / W Keller / R Valenta / S Vrtala / ; Abstract: BACKGROUND: The house dust mite (HDM) Dermatophagoides pteronyssinus is a major allergen source eliciting allergic asthma. The aim of the study was to identify new important HDM allergens associated with allergic asthma.; METHODS: A cDNA coding for a new mite allergen, designated Der p 21, was isolated using immunoglobulin E (IgE) antibodies from patients with allergic asthma out of a D. pteronyssinus expression cDNA library and expressed in Escherichia coli.; RESULTS: Circular dichroism analysis of the purified allergen showed that rDer p 21 (14 726 Da) is one of the few mite allergens with an alpha-helical secondary structure. The protein exhibited high thermal stability and refolding capacity, and, as determined by small angle X-ray scattering, formed a dimer consisting of two flat triangles. rDer p 21 bound high levels of patients' IgE antibodies and showed high allergenic activity in basophil activation experiments. Rabbit anti-Der p 21 IgG antibodies inhibited mite-allergic patients' IgE binding and allowed the ultrastructural localization of the allergen in the midgut (epithelium, lumen and faeces) of D. pteronyssinus by immunogold electron microscopy. Der p 21 revealed sequence homology with group 5 mite allergens, but IgE and IgG reactivity data and cross-inhibition studies identified it as a new mite allergen.; CONCLUSIONS: Der p 21 is a new important mite allergen which is liberated into the environment via faecal particles and hence may be associated with allergic asthma.

Contact author

• Petr Konarev (EMBL-Hamburg, European Molecular Biology Laboratory (EMBL) - Hamburg outstation, Notkestraße 85, Geb. 25A, 22607 Hamburg, Deutschland, Germany)

Models

• Model #49: ; Type: dummy / Software: dammin / Symmetry: P2 / Chi-square value: 3.493161; Search similar-shape structures of this assembly by Omokage search (details)
• Model #50: ; Type: mix / Software: Bunch / Radius of dummy atoms: 1.90 A / Symmetry: P2 / Chi-square value: 3.0625; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: Der p21 / Sample MW: 26 kDa / Specimen concentration: 4.7 mg/ml
• Buffer: Name: 10 mM Hepes / pH: 7

Entity #49

Name: Derp21 / Type: protein / Description: Der p21, allegren / Formula weight: 13 / Num. of mol.: 2 / Source: Escherichia coli
Sequence:

MFIVGDKKED EWRMAFDRLM MEELETKIDQ VEKGLLHLSE QYKELEKTKS KELKEQILRE LTIGENFMKG ALKFFEMEAK RTDLNMFERY NYEFALESIK LLIKKLDELA KKVKAVNPDE YY

Experimental information

• Beam: Instrument name: DORIS III X33 / City: Hamburg / 国: Germany / Type of source: X-ray synchrotron
• Detector: Name: MAR 345 Image Plate

Scan

Title: der p21 / Measurement date: Jul 24, 2006 / Storage temperature: 10 °C / Cell temperature: 10 °C / Exposure time: 120 sec. / Number of frames: 2 / Unit: 1/nm /

	Min	Max
Q	0.2005	4.9899

Distance distribution function P(R)

Sofotware P(R): GNOM 4.5a / Number of points: 512 /

	Min	Max
Q	0.2039	4.866
P(R) point	46	557
R	0	8.5

Result

Type of curve: single_conc /

	Experimental	Porod
MW	26 kDa	-
Volume	-	50 nm3

	P(R)	Guinier
Forward scattering, I0	134	98.1
Radius of gyration, Rg	2.75 nm	2.65 nm

	Min	Max
D	-	8.5
Guinier point	1	108