Production of ?-aminoadipate-?-semialdehyde by a mutant from Candida maltosa

Exploring the druggable proteome of Candida species through comprehensive computational analysis

Candida albicans and non-albicans Candida spp. are major cause of systemic mycoses. Antifungal drugs such as azoles and polyenes are not efficient to successfully eradicate Candida infection owing to their fungistatic nature or low bioavailability. Here, we have adopted a comprehensive computational workflow for identification, prioritization and validation of targets from proteomes of Candida albicans and Candida tropicalis. The protocol involves identification of essential drug-target candidates using subtractive genomics, protein-protein interaction network properties and systems biology based methods. The essentiality of the novel metabolic and non-metabolic targets was established by performing in silico gene knockouts, under aerobic as well as anaerobic conditions, and in vitro drug inhibition assays respectively. Deletion of twelve genes that are involved in amino acid, secondary metabolite, and carbon metabolism showed zero growth in metabolic model under simulated conditions. The algorithm, used in this study, can be downloaded from http://pbit.bicnirrh.res.in/offline.php and executed locally.

Enzymatic production of alpha-aminoadipate-delta-semialdehyde and related compounds by lysine epsilon-dehydrogenase from Candida albicans

L-Lysine epsilon-dehydrogenase [L-lysine:NADP+ oxidoreductase (epsilon-deaminating), EC 1.4.1.15] of Candida albicans was studied emphasizing its application for the production of alpha-aminoadipate-delta-semialdehyde and related compounds. A high enzyme level (240 pkat/mg of protein in the crude extract) could be attained during growth in the presence of L-lysine as sole nitrogen source. After optimization of the reaction conditions a partial purified enzyme (1.5 nkat/mg of protein) was used to produce alpha-aminoadipate-delta-semialdehyde, S-(beta-acetaldehyde)-cysteine, alpha-amino-delta-hydroxyadipate-semialdehyde and alpha-amino-gamma-hydroxyadipate-semialdehyde from the corresponding substrates lysine, S-(beta-aminoethyl)-cysteine, 5-hydroxylysine and 4-hydroxylysine, respectively. After purification of the compounds using Dowex 50 x 4 chromatography a yield of the products between 4.6 and 6.8% was achieved.