Probing the SpNOX substrate binding site for NADPH vs. NADH affinity

Probing the substrate binding site of Candida tenuis xylose reductase (AKR2B5) with site-directed mutagenesis.

Little is known about how substrates bind to CtXR (Candida tenuis xylose reductase; AKR2B5) and other members of the AKR (aldo-keto reductase) protein superfamily. Modelling of xylose into the active site of CtXR suggested that Trp23, Asp50 and Asn309 are the main components of pentose-specific substrate-binding recognition. Kinetic consequences of site-directed substitutions of these residues ...

Probing protein phosphatase substrate binding: affinity pull-down of ILKAP phosphatase 2C with phosphopeptides.

Proteomics and high throughput analysis for systems biology can benefit significantly from solid-phase chemical tools for affinity pull-down of proteins from complex mixtures. Here we report the application of solid-phase synthesis of phosphopeptides for pull-down and analysis of the affinity profile of the integrin-linked kinase associated phosphatase (ILKAP), a member of the protein phosphata...

Substrate binding and sequence preference of the proteasome revealed by active-site-directed affinity probes.

BACKGROUND The proteasome is a multicatalytic protease complex responsible for most cytosolic protein breakdown. The complex has several distinct proteolytic activities that are defined by the preference of each for the carboxyterminal (P1) amino acid residue. Although mutational studies in yeast have begun to define substrate specificities of individual catalytically active beta subunits, litt...

The substrate binding site of pepsin.

In earlier reports from this laboratory, a series of new synthetic substrates for pepsin was described.'-' These compounds are of the general type Z-His-X-YOAI\e4 where X and Y are the residues of amino acids such as L-phenylalanine, p-nitro-L-phenylalanine, L-tyrosine, L-tryptophan, and L-leucine; the enzymic action is limited to the cleavage of the X-Y bond. One of the substrate analogues pre...

PROBING THE ACTIVE SITE OF RHODANESE WITH DISULFIDE REAGENTS