Exoproteome of XXXX corneal isolates and saprophytes: Identification of proteoforms of an oversecreted alkaline protease.

@entity1 @entity267 @entity1036 @entity11792 @entity281 @entity364 @entity563
UNASSIGNED: @entity11792 infects the @entity1 eye leading to @entity1036 . Extracellular proteins, the earliest proteins that come in contact with the host and virulence related exoproteins, were identified in the fungus isolated from infected @entity267 . Virulence of the corneal isolates was tested in the Galleria mellonella larvae model and those isolates showing higher virulence were taken for subsequent exoproteome analysis. High resolution two-dimensional electrophoresis and mass spectrometry were used to generate A. flavus exoproteome reference map as well as to profile most of the exoproteins. Analysis of the identified proteins clearly shows the major biological processes that they are involved in. Nearly 50% of the exoproteins possess catalytic activity and one of these, an alkaline @entity563 protease (Alp1) is present in high abundance as well as multiple proteoforms. Many proteins in the A. flavus exoproteome have been shown to be virulence factors in other pathogens indicating the probable role for these proteins in the @entity281 as well. Interestingly, the majority of the exoproteins do not have secretory signal indicating that they are secreted through the non-classical pathway. Thus, this study provides a clue to the early strategies employed by the pathogen to establish an @entity281 in an immunocompetent host. BIOLOGICAL SIGNIFICANCE: The outcome of a @entity364 in an immunocompetent @entity1 eye depends on the ability of the fungus to overcome the host defense and propagate itself. In this process, the earliest events with respect to the fungal proteins involved include the secretory proteins of the invading organism. As a first step towards understanding the role of the extracellular proteins, exoproteome profile of the fungal isolates was generated. The fungal isolates from @entity267 showed a distinct pattern of the exoproteome when compared to the saprophyte. Since corneal isolates also showed higher virulence in the insect larval model, presumably the proteins elaborated by the corneal isolates are virulence related. One of the abundant proteins is an alkaline @entity563 protease and this protein exists as multiple proteoforms. This study reports the comprehensive profile of exoproteome and reveals proteins that are potential virulence factors.
