SASDC85: Leishmania braziliensis p23B (Leishmania braziliensis p23 isoform...

Basic information

• Entry: Database: SASBDB / ID: SASDC85

Sample

Leishmania braziliensis p23B

• Leishmania braziliensis p23 isoform B (protein), Lbp23B, Leishmania braziliensis

• Function / homology: CS domain / CS domain / CS domain profile. / HSP20-like chaperone / Contig, possible fusion of chromosomes 20 and 34
• Biological species: Leishmania braziliensis (eukaryote)
• Citation: Journal: FEBS J / Year: 2015; Title: Identification of two p23 co-chaperone isoforms in Leishmania braziliensis exhibiting similar structures and Hsp90 interaction properties despite divergent stabilities.; Authors: Fernanda A H Batista / Glessler S Almeida / Thiago V Seraphim / Kelly P Silva / Silvane M F Murta / Leandro R S Barbosa / Júlio C Borges / ; Abstract: The small acidic protein called p23 acts as a co-chaperone for heat-shock protein of 90 kDa (Hsp90) during its ATPase cycle. p23 proteins inhibit Hsp90 ATPase activity and show intrinsic chaperone activity. A search for p23 in protozoa, especially trypanosomatids, led us to identify two putative proteins in the Leishmania braziliensis genome that share approximately 30% identity with each other and with the human p23. To understand the presence of two p23 isoforms in trypanosomatids, we obtained the recombinant p23 proteins of L. braziliensis (named Lbp23A and Lbp23B) and performed structural and functional studies. The recombinant proteins share similar solution structures; however, temperature- and chemical-induced unfolding experiments showed that Lbp23A is more stable than Lbp23B, suggesting that they may have different functions. Lbp23B prevented the temperature-induced aggregation of malic dehydrogenase more efficiently than did Lbp23A, whereas the two proteins had equivalent efficiencies with respect to preventing the temperature-induced aggregation of luciferase. Both proteins interacted with L. braziliensis Hsp90 (LbHsp90) and inhibited its ATPase activity, although their efficiencies differed. In vivo identification studies suggested that both proteins are present in L. braziliensis cells grown under different conditions, although Lbp23B may undergo post-translation modifications. Interaction studies indicated that both Lbp23 proteins interact with LbHsp90. Taken together, our data suggest that the two protozoa p23 isoforms act similarly when regulating Hsp90 function. However, they also have some differences, indicating that the L. braziliensis Hsp90 machine has features providing an opportunity for novel forms of selective inhibition of protozoan Hsp90.

Contact author

• Júlio Borges (Instituto de Química de São Carlos, São Carlos - SP - Brasil)

Models

• Model #1324: ; Type: dummy / Software: (5.0) / Symmetry: P1 / Chi-square value: 2.829124 / P-value: 0.000054; Search similar-shape structures of this assembly by Omokage search (details)

Sample

• Sample: Name: Leishmania braziliensis p23B / Specimen concentration: 1.00-4.00
• Buffer: Name: 25 mM Tris-HCl, 100 mM NaCl, 5 mM B-mercaptoethanol / pH: 8

Entity #707

Name: Lbp23B / Type: protein / Description: Leishmania braziliensis p23 isoform B / Formula weight: 23.045 / Num. of mol.: 1 / Source: Leishmania braziliensis / References: UniProt: A4HAD9
Sequence:

GSHMSASGSL VPPISWAQRP EYVLVTIPLQ DTTGVTVEIK DEGRELLFAC CAPEGKQYAC TIHFYGAISS EESQHVVRPR QIELKLRKKL TRSLEDADDE VEWPRLTKEK VKYPNITIDW SKWKDEDDEG ATDDLGDFGL GGGDAMDGQY SEMLSQLMQT QGKKDAEELA GLPPGTIPEF GSAQRQEATH GASAAAGDDD SEMPPLEDDM

Experimental information

• Beam: Instrument name: Brazilian Synchrotron Light Laboratory SAXS2 Beamline; City: Campinas / 国: Brazil / Type of source: X-ray synchrotron / Wavelength: 0.1488 Å / Dist. spec. to detc.: 1 mm
• Detector: Name: MAR 165 CCD

Scan

Title: Leishmania braziliensis p23B / Measurement date: Mar 26, 2012 / Storage temperature: 4 °C / Cell temperature: 20 °C / Exposure time: 300 sec. / Unit: 1/nm /

	Min	Max
Q	0.1621	3.3455

Distance distribution function P(R)

Sofotware P(R): GNOM 4.5a / Number of points: 248 /

	Min	Max
Q	0.01621	0.3346
P(R) point	1	248
R	0	130

Result

Experimental MW: 26 kDa / Type of curve: single_conc

	P(R)	P(R) error	Guinier	Guinier error
Forward scattering, I0	0.02014	0.0004	0.0200666	0.00014
Radius of gyration, Rg	3.17 nm	0.2	3.03 nm	0.07

	Min	Max	Error
D	-	13	5
Guinier point	1	10	-