The species Amycolatopsis fastidiosa (ex Celmer et al. 1977) Henssen et al. 1987 was proposed, based on morphological and chemotaxonomic observations, for a strain originally described as 'Pseudonocardia fastidiosa' Celmer et al. 1977 in a US patent. In the course of a phylogenetic study of the taxa with validly published names within the suborder Pseudonocardineae based on 16S rRNA gene sequences, it became apparent that this species was misplaced in the genus Amycolatopsis. After careful evaluation of the phylogeny, morphology, chemotaxonomy and physiology of the type strain, it was concluded that this strain represents a species of the genus Actinokineospora that is unable to produce motile spores. The description of the genus Actinokineospora is therefore emended to accommodate species that do not produce motile spores, and it is proposed that Amycolatopsis fastidiosa be transferred to the genus Actinokineospora as Actinokineospora fastidiosa comb. nov. The type strain is NRRL B-16697(T) =ATCC 31181(T) =DSM 43855(T) =JCM 3276(T) =NBRC 14105(T) =VKM Ac-1419(T).
The objective of this study is to determine the role of carbohydrates on the toxic effect of parasporal inclusion proteins isolated from Malaysian mosquitocidal Bacillus thuringiensis (Bt) strains on erythrocytes (human and rat). Dose response analyses on the effect of these parasporal inclusions on human and rat erythrocytes suggest that toxin action is selective depending on bacterial strains and source of erythrocytes. Results from this study suggest Bt toxin is a lectin which recognizes specific plasma membrane glycoconjugate receptor(s) with a terminal residue of either D-mannose (Man), N-acetyl-D-galactosamine (GalNAc), N-acetyl-D-glucosamine (GlcNAc) or even a combination of these monosaccharides.
alpha-Galactosidase (EC 3.2.1.22) from ripe papaya (Carica papaya L.) fruit was fractionated by a combination of ion exchange and gel filtration chromatography into three forms, viz., alpha-galactosidase 1, 2 and 3. The predominant isoform, alpha-gal 2, was probably a tetramer with a native molecular mass of about 170 kDa and 52 kDa-sized subunits and an estimated pI of 7.3. The subunit's N-terminal amino acid sequence shared high identity (97%) with the deduced sequence of a papaya cDNA clone encoding a putative alpha-galactosidase PAG2 as well as with an Ajuga reptans L. GGT1 clone encoding a galactan: galactan galactosyltransferase (66%). During ripening, alpha-galactosidase activity increased concomitantly with firmness loss and this increase was largely ascribed to alpha-gal 2. The protein level of alpha-gal 2 as estimated by immunoblot was low in developing fruits and generally increased with ripening. alpha-Galactosidase 2 also had the ability to markedly catalyse increased pectin solubility and depolymerisation while the polymers were still structurally attached to the cell walls mimicking, in part, the changes that occur during ripening. The close correlation between texture changes, alpha-gal 2 activity and protein levels as well as capability to modify intact cell walls suggest that the enzyme might contribute to papaya fruit softening during ripening. The purported mechanism of alpha-gal 2 action as a softening enzyme was discussed in terms of its functional capacity as a glycanase or perhaps, as a transglycosylase.