Biochemistry of Enzymatic Pathogenicity Factors

The cuticular fatty acids of Calliphora vicina, Dendrolimus pini and Galleria mellonella larvae and their role in resistance to fungal infection

“…Although the widespread ability of fungi to grow on hydrocarbons is well known (Sancholle and Lö sel, 1995) information concerning utilization of hydrocarbons present in insect cuticle by pathogenic fungi is rare (Napolitano and Juarez, 1997). Similarly, studies on fungal lipases hydrolyzing triacylglycerols concentrate on species medically important or with biotechnological applications (Cole, 1996;Sancholle and Lö sel, 1995), while reports on lipases produced by entomopathogenic fungi are unique (Khachatorians, 1996;Gillespie et al, 2000).…”

Morphological evidence for keratinolytic activity ofScopulariopsisspp. isolates from nail lesions and the air

“…In addition, a number of other factors which are dependent on the fungus, the host and the environment, are probably required for the initiation and development of infections [39]. Expression of putative virulence genes under de ned growth conditions may not re ect the true nature of the pathogen's response in vivo [8]. Expression of putative virulence genes under de ned growth conditions may not re ect the true nature of the pathogen's response in vivo [8].…”

“…The a -keratins that abound in skin, hair, wool, nails and horns, resist degradation by most microorganisms because their polypeptide chains are tightly packed in a -helices and linked by disulphide bridges [6,7]. Biochemical techniques cannot provide reliable information concerning this activity, since the production of extracellular proteases [8] and the presence of Lowry-positive peptides [12] are not enough to show that a -keratins have been degraded. Biochemical techniques cannot provide reliable information concerning this activity, since the production of extracellular proteases [8] and the presence of Lowry-positive peptides [12] are not enough to show that a -keratins have been degraded.…”

“…Keratinolytic ability is putative virulence factor [8], since the epithelial surface of the host is the main barrier to passive fungal invasion [9], and its penetration seems to depend on enzymatic degradation of its macromolecules [9], including the keratins [10,11]. It is, in fact, uncertain whether peptides are actually released from a -keratins or other keratin-associated proteins [8]. It is, in fact, uncertain whether peptides are actually released from a -keratins or other keratin-associated proteins [8].…”

Mechanics of Solid Tissue Invasion by the Mammalian Pathogen Pythium insidiosum

“…Four proteins with molecular weights ranging from 28 to 34 kDa exhibit serine proteinase activity (these are probably catalytic subunits of one or more larger enzymes), and a 48-kDa protein has the hallmarks of a calcium-dependent metalloproteinase (based on its sensitivity to inhibitors). The in vivo expression of these enzymes and any role in tissue colonization are not established, but serine-and metallo-proteinases are implicated in many other animal mycoses (Rhodes, 1995;Cole, 1996;Ruchel, 1999). Interestingly, secreted proteinases appear to play an analogous role in reducing tissue strength to facilitate the development of invasive cancers and allow trophoblast implantation in the uterine wall (Landman and Pettet, 1998).…”