ENTRANSFOOD: EXCHANGE VISIT REPORT

 

Visitor	Harri Kokko, Department of Biochemistry, University of Kuopio, Finland; GMOCARE Partner No 10
Visit to	Julio Celis, University of Åarhus, Denmark; GMOCARE Partner No 6
Dates	24-29.07.2000
Purposes	1)      Participation in the lectures of the joint EMBO/FEBS course: '2D PAGE and mass spectrometry in cell biology' (Aarhus and Heidelberg) 2) Visit of the proteomics laboratory of JC: exchange of methodological experience (preparation of gels, electrophoresis/IEF, staining, MALDI-TOF mass spectral analysis)

The visit in Julio Celis laboratory in Århus was arranged to match the course on 2D PAGE and mass spectrometry in cell biology. I had a chance to listen to many specialist lecturers (programme annexed). The course was also an excellent contact point with product experts on 2D analysis software (Bio-Rad). The main purpose, however, was to compare the instrumentation and methodological practices of the proteomics laboratories in Århus and Kuopio. The isoelectric focusing and 2D electrophoresis equipments in Århus were made in-house; the dimensions of the gels were different from those in Kuopio and therefore the inter-laboratory comparison is not quite possible. Silver staining in Århus and Kuopio did not differ significantly; they are compatible to tryptic digestion and MALDI-TOF mass spectrometer. The methods can be, if necessary, adjusted so that the same method is used in both laboratories. However, the differences in the gels and equipments cause some limitations to the comparison. Metabolic labelling by methionine, used in Århus, is excellent for cell cultures but cannot be applied to the plant material in the GMOCARE project. The storage of 2D gels in Århus was solved by drying them between cellophane sheets in air by using KemTek drying frames. Similar drying frames were purchased also to Kuopio. In gel- sample preparation for tryptic digestion in Århus is a standard method using Ziptip® approach that can be taken into use easily in any laboratory. Standardisation of MALDI mapping on tryptic digests with peptides from trypsin improves the accuracy of the determination of the peptide masses; this improves the chances to identify the peptides from databases. Similar Brueker Biflex instrument is in use in both Århus and Kuopio making the collaboration and information exchange easier between the two laboratories. Method for protein isolation is different in the laboratories. Samples of isolated potato proteins were taken from Kuopio to Århus but there was no chance to run them during the visit; the samples were run later in Århus. Altogether, the visit was very useful.