Oh S W, Jeon K W
Department of Biochemistry, University of Tennessee, Knoxville, USA.
J Eukaryot Microbiol. 1998 Nov-Dec;45(6):600-5. doi: 10.1111/j.1550-7408.1998.tb04555.x.
Monoclonal antibodies against the myosin heavy chain of Amoeba proteus were obtained and used to localize myosin inside amoebae and to clone cDNAs encoding myosin. Myosin was found throughout the amoeba cytoplasm but was more concentrated in the ectoplasmic regions as determined by indirect immunofluorescence microscopy. In symbiont-bearing xD amoebae, myosin was also found on the symbiosome membranes, as checked by indirect immunofluorescence microscopy and by immunoelectron microscopy. The open reading frame of a cloned myosin cDNA contained 6,414 nucleotides, coding for a polypeptide of 2,138 amino acids. While the amino-acid sequence of the globular head region of amoeba's myosin had a high degree of similarity with that of myosins from various organisms, the tail region building a coiled-coil structure did not show a significant sequence similarity. There appeared to be at least three different isoforms of myosins in amoebae, with closely related amino acids in the globular head region.
获得了抗变形虫肌球蛋白重链的单克隆抗体，并用于在变形虫内定位肌球蛋白以及克隆编码肌球蛋白的cDNA。通过间接免疫荧光显微镜观察发现，肌球蛋白存在于整个变形虫细胞质中，但在外质区域更为集中。通过间接免疫荧光显微镜和免疫电子显微镜检查发现，在携带共生体的xD变形虫中，肌球蛋白也存在于共生体膜上。克隆的肌球蛋白cDNA的开放阅读框包含6414个核苷酸，编码一个由2138个氨基酸组成的多肽。虽然变形虫肌球蛋白球状头部区域的氨基酸序列与来自各种生物体的肌球蛋白具有高度相似性，但形成卷曲螺旋结构的尾部区域并未显示出明显的序列相似性。变形虫中似乎至少存在三种不同的肌球蛋白同工型，其球状头部区域的氨基酸密切相关。
