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The presence of various enzyme forms with terminal action pattern on pectate was evaluated in a protein mixture obtained from parsley roots. Enzymes found in the soluble fraction of roots (juice) were purified to homogeneity according to SDS-PAGE, partially separated by preparative isoelectric focusing and characterized. Three forms with pH optima 3.6, 4.2 and 4.6 clearly preferred substrates with a lower degree of polymerization (oligogalacturonates) while the form with pH optimum 5.2 was a typical exopolygalacturonase [EC 3. 2.1.67] with relatively fast cleavage of polymeric substrate. The forms with pH optima 3.6, 4.2 and 5.2 were released from the pulp, too. The form from the pulp with pH optimum 4.6 preferred higher oligogalacturonates and was not described in plants previously. The production of individual forms in roots was compared with that produced by root cells cultivated on solid medium and in liquid one.

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This study was undertaken to investigate the effect of the malting process on hordein composition. For this purpose, combination of sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) and the method of isotopic peptides labeling iTRAQ was used. Barley proteins are essential components determining the quality of both malt and beer. Since hordeins represent the most abundant proteins accounting for about 40-50% of total protein fraction of mature barley grain, our research was focused on them. In this respect, the proteins of interest were extracted from milled samples of barley grain, germinated barley grain (samples collected at different time intervals), green malt and malt, respectively. Particular hordein extracts were firstly fractionated via SDS-PAGE, which was used as a relatively rapid and reliable technique providing information about hordein profile of analyzed samples. Then, separated proteins were in-gel digested and resulting peptides were measured by mass spectrometry. In addition, the chosen proteins, after in-gel digestion, were subjected to the iTRAQ method and the screening of proteins during malting process was evaluated. Our results have revealed that most of the hordein components present in the barley grain can be found in all stages of the malting process as well as in the final malt. The amount of hordeins decreases during the malting process; in the case of C hordein, the protein decrease is approximately 65%. On the other hand, significant degradation of D hordein was detected. The suggested procedure can be used to follow the development of the hordein profile during germination, which is of great technological importance in beer production.