Novel clear native electrophoresis using modified CBB G-250

2014 ◽  
Vol 58 (2) ◽  
pp. 18-20
Author(s):  
Tomoya Hino ◽  
So Iwata ◽  
Takeshi Murata
2000 ◽  
Vol 11 (1) ◽  
pp. 103-116 ◽  
Author(s):  
Oliver Kerscher ◽  
Naresh B. Sepuri ◽  
Robert E. Jensen

The mitochondrial inner membrane contains two separate translocons: one required for the translocation of matrix-targeted proteins (the Tim23p-Tim17p complex) and one for the insertion of polytopic proteins into the mitochondrial inner membrane (the Tim54p-Tim22p complex). To identify new members of the Tim54p-Tim22p complex, we screened for high-copy suppressors of the temperature-sensitivetim54-1 mutant. We identified a new gene,TIM18, that encodes an integral protein of the inner membrane. The following genetic and biochemical observations suggest that the Tim18 protein is part of the Tim54p-Tim22p complex in the inner membrane: multiple copies of TIM18 suppress thetim54-1 growth defect; thetim18::HIS3 disruption is synthetically lethal with tim54-1; Tim54p and Tim22p can be coimmune precipitated with the Tim18 protein; and Tim18p, along with Tim54p and Tim22p, is detected in an ∼300-kDa complex after blue native electrophoresis. We propose that Tim18p is a new component of the Tim54p-Tim22p machinery that facilitates insertion of polytopic proteins into the mitochondrial inner membrane.


2019 ◽  
Vol 201 (7) ◽  
Author(s):  
Lydia J. Kreuter ◽  
Andrea Weinfurtner ◽  
Alexander Ziegler ◽  
Julia Weigl ◽  
Jan Hoffmann ◽  
...  

ABSTRACTIn this study, the ATP synthase ofIgnicoccus hospitaliswas purified, characterized, and structurally compared to the respective enzymes of the otherIgnicoccusspecies, to shed light on energy conservation in this unique group of archaea. The crenarchaeal genusIgnicoccuscomprises three described species, i.e.,I. hospitalisandIgnicoccus islandicusfrom hot marine sediments near Iceland andIgnicoccus pacificusfrom a hydrothermal vent system in the Pacific Ocean. This genus is unique among all archaea due to the unusual cell envelope, consisting of two membranes that enclose a large intermembrane compartment (IMC).I. hospitalisis the best studied member of this genus, mainly because it is the only known host for the potentially parasitic archaeonNanoarchaeum equitans.I. hospitalisgrows chemolithoautotrophically, and its sole energy-yielding reaction is the reduction of elemental sulfur with molecular hydrogen, forming large amounts of hydrogen sulfide. This reaction generates an electrochemical gradient, which is used by the ATP synthase, located in the outer cellular membrane, to generate ATP inside the IMC. The genome ofI. hospitalisencodes nine subunits of an A-type ATP synthase, which we could identify in the purified complex. Although the maximalin vitroactivity of theI. hospitalisenzyme was measured around pH 6, the optimal stability of the A1AOcomplex seemed to be at pH 9. Interestingly, the soluble A1subcomplexes of the differentIgnicoccusspecies exhibited significant differences in their apparent molecular masses in native electrophoresis, although their behaviors in gel filtration and chromatography-mass spectrometry were very similar.IMPORTANCETheCrenarchaeotarepresent one of the major phyla within theArchaeadomain. This study describes the successful purification of a crenarchaeal ATP synthase. To date, all information about A-type ATP synthases is from euryarchaeal enzymes. The fact that it has not been possible to purify this enzyme complex from a member of theCrenarchaeotauntil now points to significant differences in stability, possibly caused by structural alterations. Furthermore, the study subjectI. hospitalishas a particular importance among crenarchaeotes, since it is the only known host ofN. equitans. The energy metabolism in this system is still poorly understood, and our results can help elucidate the unique relationship between these two microbes.


1998 ◽  
Vol 333 (1) ◽  
pp. 151-158 ◽  
Author(s):  
Annamaria PALMISANO ◽  
Vincenzo ZARA ◽  
Angelika HÖNLINGER ◽  
Angelo VOZZA ◽  
Peter J. T. DEKKER ◽  
...  

We have studied the targeting and assembly of the 2-oxoglutarate carrier (OGC), an integral inner-membrane protein of mitochondria. The precursor of OGC, synthesized without a cleavable presequence, is transported into mitochondria in an ATP- and membrane potential-dependent manner. Import of the mammalian OGC occurs efficiently into both mammalian and yeast mitochondria. Targeting of OGC reveals a clear dependence on the mitochondrial surface receptor Tom70 (the 70 kDa subunit of the translocase of the outer mitochondrial membrane), whereas a cleavable preprotein depends on Tom20 (the 20 kDa subunit), supporting a model of specificity differences of the receptors and the existence of distinct targeting pathways to mitochondria. The assembly of minute amounts of OGC imported in vitro to the dimeric form can be monitored by blue native electrophoresis of digitonin-lysed mitochondria. The assembly of mammalian OGC and fungal ADP/ATP carrier occurs with high efficiency in both mammalian and yeast mitochondria. These findings indicate a dynamic behaviour of the carrier dimers in the mitochondrial inner membrane and suggest a high conservation of the assembly reactions from mammals to fungi.


Sign in / Sign up

Export Citation Format

Share Document