Electrophoretic Studies of Soluble Proteins from Aspergillus Spp.

Abstract

Soluble proteins from 5 members of the Aspergillus flavus group (i.e., A. flavus Link, A. leporis States & Christensen, A. oryzae (Ahlb.) Cohn, A. parasiticus Speare, and A. tamarii Kita), A. fumigatus Fresenius, and A. ochraceus Wilhelm were fractionated by Polyacrylamide gel electrophoresis. Preparations from A. fumigatus exhibited 48 protein fractions, those from A. flavus and A. oryzae each exhibited 47, there were 43 from A. parasiticus, and A. ochraceus, A. tamarii, and A. leporis showed 32, 31, and 29 fractions, respectively. Comparison of each of these 7 Aspergillus spp. with one another for homologous protein fractions seemed to indicate that more protein components are shared among A. flavus, A. oryzae, and A. parasiticus than between A. flavus and A. fumigatus. However, comparison between A. fumigatus and A. parasiticus revealed the same number of homologous proteins exhibited by A. oryzae and A. parasiticus. Our results did not support the contention that A. flavus and A. parasiticus may be more closely related to each other than to other members of the A. flavus group. It appeared however that A. flavus and A. oryzae may be more closely related. Protein preparations from all 7 taxa contained 2 common protein fractions. Preparations from the S species of the A. flavus group had 2 other common protein fractions not found in A. fumigatus or A. ochraceus. The 3 strains of each of the 7 Aspergillus spp. used in this investigation did not contain the same protein complements. These strains differed only in minor morphological characteristics but may have differed significantly in some of their biochemical processes.