Probing the Channel-BoundShakerB Inactivating Peptide by Stereoisomeric Substitution at a Strategic Tyrosine Residue†

Probing the channel-bound shaker B inactivating peptide by stereoisomeric substitution at a strategic tyrosine residue.

A synthetic peptide patterned after the sequence of the inactivating ball domain of the Shaker B K(+) channel, the ShB peptide, fully restores fast inactivation in the deletion Shaker BDelta6-46 K(+) channel, which lacks the constitutive ball domains. On the contrary, a similar peptide in which tyrosine 8 is substituted by the secondary structure-disrupting d-tyrosine stereoisomer does not. Thi...

Tyrosine phosphorylation of the inactivating peptide of the shaker B potassium channel: a structural-functional correlate.

A synthetic peptide patterned after the sequence of the inactivating "ball" domain of the Shaker B K(+) channel restores fast (N-type) inactivation in mutant deletion channels lacking their constitutive ball domains, as well as in K(+) channels that do not normally inactivate. We now report on the effect of phosphorylation at a single tyrosine in position 8 of the inactivating peptide both on i...

Synthesis of a photoaffinity labeling analogue of the inactivating peptide of the Shaker B potassium channel.

A photoactivatable derivative of the inactivating peptide of the Shaker B potassium channel (ShB peptide) has been synthesized from ShB peptide containing an added cysteine residue at the peptide carboxy-terminus and 1-(p-azidosalicylamido)-4-(iodoacetamido)butane. The peptide derivative restores rapid inactivation in the deletion mutant Shaker Bdelta6-46 potassium channel in a manner indisting...

Peptide and Protein Delivery at a Glance

Peptide and protein drugs have found an important position in therapeutics. Recent advances in pharmaceutical biotechnology have led to an increase in the number of protein products in the market. As these therapeutic proteins and peptides are made available, it will be essential to formulate these drugs into safe and effective delivery systems. The twenty different naturally occurring amin...

Probing with TCR-Like Recombinant Conformation of the MHC-Peptide Complex: an HLA-A2 Anchor Residue Can Alter the Modification of a Tumor-Derived Peptide at