Misra Gauri, Ramachandran Ravishankar
Central Drug Research Institute, CSIR, Lucknow, India.
Biochim Biophys Acta. 2010 Nov;1804(11):2146-52. doi: 10.1016/j.bbapap.2010.08.007. Epub 2010 Aug 21.
Plasmodium falciparum harbors an essential relict plastid called the apicoplast that is involved in several important biosynthetic processes. Over 500 nuclear encoded proteins are imported into the organelle that is now recognized as an important therapeutic target. These proteins contain an N-terminal transit peptide sequence essential for apicoplast targeting during which the P. falciparum Hsp70-1 plays an important role. In the present study, we have focused on the in vitro interactions of PfHsp70-1 with synthetic peptides endowed with transit peptide like features. The peptides exhibit higher affinity for PfHsp70-1 in the presence of ADP compared to ATP. The results highlight the positional importance of selected residues in the designed peptides for affinity. They suggest that better peptide affinity for the protein requires a Lys at second position, retention of aromatic residue at the last position, and absence of acidic residues at any position in the transit peptides. Overall, the present work is the first in vitro fluorescence-based study of PfHsp70-1 with peptides possessing transit peptide-like features.
恶性疟原虫含有一种名为顶质体的必需残余质体，它参与多种重要的生物合成过程。超过500种核编码蛋白被导入该细胞器，现在它被认为是一个重要的治疗靶点。这些蛋白含有一个N端转运肽序列，这对于顶质体靶向至关重要，在此过程中恶性疟原虫热休克蛋白70-1（PfHsp70-1）发挥重要作用。在本研究中，我们聚焦于PfHsp70-1与具有类似转运肽特征的合成肽的体外相互作用。与ATP存在时相比，这些肽在ADP存在时对PfHsp70-1表现出更高的亲和力。结果突出了设计肽中所选残基对亲和力的位置重要性。它们表明，肽对该蛋白具有更好的亲和力需要在第二位有一个赖氨酸，在最后一位保留芳香族残基，并且在转运肽的任何位置都不存在酸性残基。总体而言，本研究是首次对PfHsp70-1与具有类似转运肽特征的肽进行基于荧光的体外研究。
