Comparison of biochemical and immunochemical properties of myosin II in taeniid parasites

Abstract

Type II myosins are highly conserved proteins, though differences have been observed among organisms, mainly in the filamentous region. Myosin isoforms have been identified in Taenia solium, a helminth parasite of public health importance in many developing countries. These isoforms are probably associated with the physiological requirements of each developmental stage of the parasite. In this paper we extend the characterization of myosin to several other Taenia species. Type II myosins were purified from the larvae (cysticerci) of Taenia solium, T. taeniaeformis and T. crassiceps and the adult stages of T. solium, T. taeniaeformis and T. saginata. Rabbit polyclonal antibodies against some of these myosins were specific at high dilutions but cross-reacted at low dilutions. ATPase activity was evaluated and kinetic values were calculated for each myosin. Homologous actin-myosin interactions increased both the affinity of myosin for ATP and the hydrolysis rate. The results indicate immunological and biochemical differences among taeniid myosins. This variability suggests that different isoforms are found not only in different taeniid species but also at different developmental stages. Further characterization of myosin isoforms should include determination of their amino acid composition.

Shared Gene Structures and Clusters of Mutually Exclusive Spliced Exons within the Metazoan Muscle Myosin Heavy Chain Genes

“…The exons of cluster-8 encode different versions of loop-2 [4], which comprises an important part of the actin-binding site, and the Platyhelminthes can thus express muscle myosins with modulated actin-binding properties. So far, only muscle myosins of the cestode parasite Taenia solium have been investigated biochemically [29], [30]. Taenia exists in two developmental stages, cysticerci (larvae) and tapeworms (adults).…”

Vaccines Against Cysticercosis

“…The distribution off the vaccine antigens among the regional or world population of all taenia specimens is not known with any precision. What is well known is that there are numerous antigens common to different species of taenias and even among other cestodes [6,48,49], as it occurs with the antigens used in immunodiagnosis [48,50,51]. Considering the genetic differences reported among cysticerci recovered from pigs of different regions of Mexico and other countries of the world [52,53], common antigens are of great interest for vaccine design because they imply that a single vaccine could possibly prevent a wide spectrum of cestode diseases.…”

Proteomic study of activated Taenia solium oncospheres

“…We have found a set of proteins not described before in T. solium oncospheres, with the exception of the oncospheral stage-specific antigen Tso22a [6]. Some others have been specifically characterized in T. solium adult worms and cysticerci, including actins [15], antigen 5 [16], paramyosin (AgB) [17], myosin [18], GST [19], SOD [20], cytochrome B [21], and Tsa p36 (crystallin) [22] and other heat-shock proteins [23]. Some of them have shown to play crucial roles in host-parasite relationships, e.g.…”