Possible Interaction: Alanine and Tryptophan

“However, the replacement of Trp in each of the four putative copper‐binding domains by Ala slightly decreased its potency.”

“Replacing Trp 659 … site A or Trp 692 at … B to Ala reduces binding by 22- and 31-fold (Kd = 2.9 x 10(-6) and 4.0 x 10(-6) M), respectively, and destabilizes the CaD39-calmodulin complex by 1.75 and 1.94 kcal mol-1, respectively.”

“We also found that D-isomers were about 1/3 as effective as L-isomers to inhibit L-tryptophan uptake.”

“Exchange of Trp to Ala in subsite -3 resulted in a 12-fold reduction in extent of degradation and a 20-fold reduction in kcat(app) on chitin, while the values are 5-fold and 10-fold for subsite +2.”

“This study set out to elucidate how Ii regulates ULBP2 cell-surface transport: We discovered conserved tryptophan (Trp) … in the primary protein sequence of ULBP1-6 but not in the related MICA/B. Substitution of Trp … alanine resulted in cell-surface inhibition of ULBP2 in different cancer cell lines.”

“Replacements of the central Trp‐Trp pair with Ala‐Ala , His‐His, or Phe‐Phe residues in the PxxP motif significantly affects the ability of the peptide to stabilize duplex DNA.”

“Substitution of Tyr¹, Trp⁴ , Arg⁷ and Trp⁸ to Ala resulted in a marked drop in affinity.”

“Substitution of alanine for tryptophan at position 9 significantly decreased both the rate of adsorption/insertion of the peptide into the interface and reinsertion of surface-active material excluded from the film during successive compression-expansion cycles.”

“Mutation of conserved tryptophan residues W47, W93, and W106 in the FnII domains of PDC‐109 to alanine leads to drastic decrease or complete abolition of membrane‐binding and chaperone‐like activities.”

“Replacement of this tryptophane by alanine decreased the activity to 70.3% and made it susceptible to heat and denaturants, such as GdnHCl.”