Although the protozoan parasite,Trypanosoma brucei, can acquire lipids
from its environment, recent reports have shown that it is also capable of
de novo synthesis of all major phospholipids. Here we provide an over-view of the biosynthetic pathways involved in phospholipid formation in
Mầm bệnh: Mầm bệnh của bệnh ngủ châu Phi là Trypanosoma brucei. Trong đó, ở Đông Phi chủ yếu gặp chủng T.brucei rhodesiene, còn ở Tây và Trung Phi gặp chủ yếu là T.b. gambiense. Giữa hai chủng ký sinh trùng này khó phân biệt nhau. T.b. rhodesiene thường có độc tính cao hơn, gây bệnh nặng hơn và tiến triển nhanh. T.b. gambiense thường có diễn biến mạn tính.
3.2. Dịch tễ học:
3.2.1. Nguồn bệnh:
- Đối với T.b.
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: Repetitive DNA is associated with centromeric domains in Trypanosoma brucei but not Trypanosoma cruzi
Nfs-like proteins have cysteine desulfurase (CysD) activity, which removes
sulfur (S) from cysteine, and provides S for iron–sulfur cluster assembly
and the thiolation of tRNAs. These proteins also have selenocysteine lyase
activityin vitro, and cleave selenocysteine into alanine and elemental sele-nium (Se).
This study reports the identiﬁcation and characterization of the regulatory subunit, TbRSU, of protein kinase A of the parasitic protozoon Trypanosoma brucei. TbRSU is coded for by a single copy gene. The protein contains an unusually long N-terminal domain, the pseudosubstrate site involved in binding and inactivation of the catalytic subunit, and two C-terminally located, closely spaced cyclic nucleotide binding domains.
Trypanosoma brucei is the cause of the diseases known as sleeping sickness in humans (T. brucei ssp. gambiense and ssp. rhodesiense) and ngana in domestic animals (T. brucei brucei) in Africa. Procyclic trypomastigotes, the tsetse vector stage, express a surface-bound trans-sialidase that transfers sialic acid to the glycosylphosphatidylinositol anchor of procyclin, a surface glycoprotein covering the parasite surface. Trans-sialidase is a unique enzyme expressed by a few trypanosomatids that allows them to scavenge sialic acid from sialylated compounds present in the infected host. ...
Tuyển tập các báo cáo nghiên cứu về y học được đăng trên tạp chí y học Minireview cung cấp cho các bạn kiến thức về ngành y đề tài: Genetic analysis of the human infective trypanosome Trypanosoma brucei gambiense: chromosomal segregation, crossing over, and the construction of a genetic map...
In this article, we report the results of an analysis of the
glycolytic enzyme enolase (2-phospho-D-glycerate hydro-lase) of Trypanosoma brucei. Enolase activity was detected
in both bloodstream-form and procyclic insect-stage try-panosomes, although a 4.5-fold lower specific activity was
found in the cultured procyclic homogenate. Subcellular
localization analysis showed that the enzyme is only pre-sent in the cytosol.
African trypanosomes possess high levels of alanine aminotransferase (EC
22.214.171.124), although the function of their activity remains enigmatic, espe-cially in slender bloodstream forms where the metabolism of ketoacids does
not occur. Therefore, the gene for alanine aminotransferase enzyme inTry-panosoma brucei(TbAAT) was characterized and its function assessed using
a combination of RNA interference and gene knockout approaches.
Enolase is a validated drug target inTrypanosoma brucei. To better charac-terize its properties and guide drug design efforts, we have determined six
new crystal structures of the enzyme, in various ligation states and confor-mations, and have carried out complementary molecular dynamics simula-tions.
An open reading frame with fatty acid desaturase similarity
was identified in the genome ofTrypanosoma brucei.The
1224 bp sequence specifies a proteinof 408 amino acids with
59% and 58% similarity toMortierella alpinaandArabid-opsis thalianaD12 desaturase, respectively, and 51% with
A. thalianax3 desaturases. The histidine tracks that com-pose the iron-binding active centers of the enzyme were
more similar to those of thex3 desaturases.
Cell exposure to hypo-osmolarity and alkalinity triggers a spectrum of
responses including activation of phospholipases. Glycosylphosphatidyl-inositol-specific phospholipase C (GPI-PLC) is expressed in Trypanosoma
brucei, a protozoan parasite that causes human African trypanosomia-sis.
Papain-like cysteine proteases of pathogenic protozoa play important roles
in parasite growth, differentiation and host cell invasion. The main cysteine
proteases of Trypanosoma cruzi(cruzipain) and of Trypanosoma brucei
(brucipain) are validated targets for the development of new chemothera-pies.
Cyclic nucleotide specific phosphodiesterases (PDEs) are
important components of all cAMP signalling networks.
In humans, 11 different PDE families have been identified to
date, all of which belong to the class I PDEs. Pharmaco-logically, theyhavebecome of great interest as targets for the
development of drugs for a large variety of clinical condi-tions. PDEs in parasitic protozoa have not yet been exten-sively investigated, despite their potential as antiparasitic
6-Phosphogluconate dehydrogenase is a potential target for new drugs
against African trypanosomiasis. Phosphorylated aldonic acids are strong
inhibitors of 6-phosphogluconate dehydrogenase, and 4-phospho-d-erythro-nate (4PE) and 4-phospho-d-erythronohydroxamate are two of the stron-gest inhibitors of theTrypanosoma bruceienzyme.
It has been shown previously in various organisms that the
peroxin PEX14 is a component of a docking complex at the
peroxisomalmembrane,where it is involved in the import of
matrix proteins into the organelle after their synthesis in the
cytosol and recognition by a receptor. Here we present a
characterization of theTrypanosoma bruceihomologue of
PEX14. It is shown that the protein is associated with gly-cosomes,the peroxisome-like organelles of trypanosomatids
in which most glycolytic enzymes are compartmentalized....