Isoenzyme analysis of lichen algae in immobilized pH gradients

Abstract

A base for a modern species' concept of chlorococcal algae can be obtained not by morphological analysis, but by biochemical characters, e.g. isoenzyme banding patterns. From isolated lichen algae of the genus Trebouxia de Puymaly a set of five such enzymes has been studied by isoelectric focusing in immobilized pH gradients (IPG): phosphoglucomutase, phosphoglucose isomerase, malate dehydrogenase, mannitol dehydrogenase and leucine aminopeptidase. The first four are resolved into isoforms in a pH 4-7 IPG interval, while the last one is analyzed in an IPG pH 3.5-5 span. The patterns are specific for distinct populations, inter- and intraspecifically varying in dependence from their geographical distribution or the lichen species from which they have been isolated. Their limited heterogeneity (one to four isoforms) suggests that they are the products of specific genes rather than artefacts of the extraction procedure or the IPG analysis. Sharp isozyme patterns can only be obtained in a mixed-bed, carrier-ampholyte (CA)-IPG gel and by anodic application, suggesting that the recently proposed mechanism of hydrophobic protein-IPG matrix interaction (Electrophoresis, 1987, 8, 62-70) is fully operative here. As an additional mechanism, it is proposed that, in some cases, CA might simply act, when added to an IPG gel, by buffering, in the transient state, the sample zone before the protein migrates from the liquid phase into the IPG matrix.

Analysis of the Proteomic Profiling of Brain Tissue in Alzheimer′s Disease

“…It was noted quite quickly that the resolution of some hydrophobic proteins (membrane proteins) was poor and others were lost when separated by IPGs. It is thought that this is because of hydrophobic interactions between the proteins and the basic acrylamide derivatives of the IPG matrix [42]. More recently the protein patterns of some membrane preparations were compared on CA-IEF or IPG-IEF 2-D [43].…”

Genetic diversity of sterile culturedTrebouxiaphotobionts associated with the lichen-forming fungusXanthoria parietinavisualized with RAPD-PCR fingerprinting techniques

“…The prerequisites were sterile cultured isolates maintained under defined conditions and cultures of type species for comparison (Tschermak-Woess 1988). Later, the photobiont diversity within thalli of conspecific lichen-forming fungi were biochemically analysed, the focus being on isoenzyme patterns (Kilias 1988; Kilias et al 1988; Fahselt 1989). With molecular techniques and algal-specific primers applied to whole lichen DNA, the photobionts can be conveniently identified at the species level without any isolation and culturing (Beck et al 1998; Friedl et al 2000; Dahlkild et al 2001; Helms et al 2001; Beck et al 2002).…”

Carotenoids in lichens from the Swiss Alps

“…In order to achieve a more precise identification of species of the various lichens, to so-termed chemotaxonomy is being increasingly applied (HAWKSWORT 1976;LEUCKERT 1985). Todate the presence of different lichen acids (CULBERSON and KRISTIANSSON 1970), various aromatic substances (HUOVINEN et al 1989a, b;HUNECK et al 1989) and recently, even isoenzymes ( KILIAS et al 1988) in the lichens has been employed for the purpose. Chemotaxonomic studies have shown that the morphological criteria for the classification of species of lichen are not always reliable (CHRISTENSEN 1987;Ruoss 1987).…”