✍ Scribed by Sai-Ming Ngai; Robert S. Hodges
No coin nor oath required. For personal study only.
The N‐terminal regulatory region of Troponin I, residues 1–40 (TnI 1–40, regulatory peptide) has been shown to have a biologically important function in the interactions of troponin I and troponin C. Truncated analogs corresponding to shorter versions of the N‐terminal region (1–30, 1–28, 1–26) were synthesized by solid‐phase methodology. Our results indicate that residues 1–30 of TnI comprises the minimum sequence to retain full biological activity as measured in the acto‐S1‐TM ATPase assay. Binding of the TnI N‐terminal regulatory peptides (TnI 1–30 and the N‐terminal regulatory peptide (residues 1–40) labeled with the photoprobe benzoylbenzoyl group, BBRp) were studied by gel electrophoresis and photochemical cross‐linking experiments under various conditions. Fluorescence titrations of TnI 1–30 were carried out with TnC mutants that carry a single tryptophan fluorescence probe in either the N‐ or C‐domain (F105W, F105W/C domain (88–162), F29W and F29W/N domain (1–90)) (Fig. 1). Low Kd values (Kd < 10^−7^ M) were obtained for the interaction of F105W and F105W/C domain (88–162) with TnI 1–30. However, there was no observable change in fluorescence when the fluorescence probe was located at the N‐domain of the TnC mutant (F29W and F29W/N domain (1–90)). These results show that the regulatory peptide binds strongly to the C‐terminal domain of TnC. © 2001 Wiley‐Liss, Inc.
📜 SIMILAR VOLUMES
The Ca(2+)/Mg(2+)-dependent interactions between TnC and TnI play a critical role in regulating the 'on' and 'off' states of muscle contraction as well as maintaining the structural integrity of the troponin complex in the off state. In the present study, we have investigated the binding interaction
An association between cyclin D3 and the C-terminal domain of pRb2/p130 was demonstrated using the yeast two-hybrid system. Further analysis restricted the epitope responsible for the binding within the 74 N-terminal amino acids of cyclin D3, independent of the LXCXE amino acid motif present in the
## Abstract TCR signaling leads to the activation of kinases such as inducible tyrosine kinase (Itk), a key regulatory protein in T‐lymphocyte activation and function. The homolog of Itk in B cells is Bruton's tyrosine kinase, previously shown to bind and phosphorylate the transcription factor TFII