Ikebe M, Reardon S, Fay F S
Department of Physiology and Biophysics, Case Western Reserve University, Cleveland, OH 44106-4970.
FEBS Lett. 1992 Nov 9;312(2-3):245-8. doi: 10.1016/0014-5793(92)80944-c.
Myosin light chain kinase (MLCK) contains the autoinhibitor sequence right next to the N-terminus side of the calmodulin binding region. In this paper, the structural requirement of the inhibition of MLCK activity was studied using synthetic peptide analogs. Peptides Ala-783-Lys-799 and Ala-783-Arg-798 inhibited calmodulin independent MLCK at the same potency as the peptide Ala-783-Gly-804. Deletion of Arg-797-Lys-799 or substitution of these residues to Ala markedly increased the Ki while the substitution of Lys-792 and Lys-793 to Ala and the deletion of Lys-784-Lys-785 did not affect the inhibitory activity of the peptides. The results suggest that Arg-797-Arg-798 are especially important for the inhibitory activity among other basic residues in the autoinhibitory region.
肌球蛋白轻链激酶（MLCK）在钙调蛋白结合区域的N端旁边包含自身抑制序列。在本文中，使用合成肽类似物研究了抑制MLCK活性的结构要求。肽Ala-783-Lys-799和Ala-783-Arg-798对钙调蛋白非依赖性MLCK的抑制效力与肽Ala-783-Gly-804相同。缺失Arg-797-Lys-799或将这些残基替换为Ala会显著增加Ki，而将Lys-792和Lys-793替换为Ala以及缺失Lys-784-Lys-785并不影响肽的抑制活性。结果表明，在自身抑制区域的其他碱性残基中，Arg-797-Arg-798对抑制活性尤为重要。
