scholarly journals Studies on Biological Active Compounds of the Salivary Glands in Blood Sucking Insects and Ticks : Anti-coagulants in Rhodnius prolixus

1996 ◽  
Vol 47 (2) ◽  
pp. 201
Author(s):  
Yasuo Chinzei ◽  
Jianxin Sun ◽  
Masao Yuda ◽  
Masahiro Yamaguchi ◽  
Ken Miura ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Rhodnius Prolixus ◽  
Active Compounds ◽  
Blood Sucking

scholarly journals Purification and characterization of prolixin S (nitrophorin 2), the salivary anticoagulant of the blood-sucking bug Rhodnius prolixus

1995 ◽  
Vol 308 (1) ◽  
pp. 243-249 ◽  
Author(s):  
J M C Ribeiro ◽  
M Schneider ◽  
J A Guimarães
Keyword(s):  
Cation Exchange ◽  
Salivary Glands ◽  
Coagulation Factor ◽  
Rhodnius Prolixus ◽  
Exchange Chromatography ◽  
Factor X ◽  
Blood Sucking ◽  
Weak Cation Exchange ◽  
Haem Protein ◽  
Strong Cation Exchange Chromatography

The salivary anticoagulant of the blood-sucking bug Rhodnius prolixus was purified to homogeneity using a protocol consisting of weak cation-exchange, DEAE, hydrophobic-interaction and octadecyl reverse-phase chromatography, yielding a protein with the same N-terminal sequence as nitrophorin 2, one of the four NO haem protein carriers present in the salivary glands of Rhodnius with a molecular mass of 19689 Da [D. Champagne, R.H. Nussenzveig and J.M.C. Ribeiro, (1995) J. Biol. Chem. 270, in the press]. To exclude the possibility of the nitrophorin being a contaminant, another chromatographic protocol was performed, consisting of chromatofocusing followed by strong-cation-exchange chromatography. Again the anticoagulant was eluted with nitrophorin 2. Nitrophorin 2 inhibits coagulation Factor VIII-mediated activation of Factor X and accounts for all the anti-clotting activity observed in Rhodnius salivary glands.

scholarly journals Nitric oxide loading of the salivary nitric-oxide-carrying hemoproteins (nitrophorins) in the blood-sucking bug Rhodnius prolixus.

1995 ◽  
Vol 198 (5) ◽  
pp. 1093-1098
Author(s):  
R H Nussenzveig ◽  
D L Bentley ◽  
J M Ribeiro
Keyword(s):  
Nitric Oxide ◽  
Epithelial Cells ◽  
Salivary Glands ◽  
Rhodnius Prolixus ◽  
Malpighian Tubules ◽  
Nadph Diaphorase ◽  
No Production ◽  
Synthetase Activity ◽  
Diaphorase Activity ◽  
Blood Sucking

The salivary glands of the blood-sucking bug Rhodnius prolixus are formed by a single layer of binucleated epithelial cells surrounded by a double layer of transversely oriented smooth muscle cells. The epithelial cells are rich in rough endoplasmic reticulum and mitochondria and have abundant microvillar projections towards the gland lumen. This cell layer surrounds a relatively large cavity where abundant secretory material is stored. Epithelial cells produce an intense and generalized NADPH diaphorase reaction, in contrast to other tissues such as brain, Malpighian tubules and skeletal muscle. Ultrastructural analysis of the osmiophilic reaction product indicates that it is localized within cytoplasmic vacuoles, a similar location to that of NADPH diaphorase (NO synthetase) activity in neuronal cells of vertebrates. Measurements of the time course of protein accumulation, NADPH diaphorase activity and the degree of nitrosylation of hemoproteins (nitrophorins) in the salivary glands of Rhodnius prolixus nymphs after a blood meal indicate that the nitrophorins are synthesized and accumulate when NO production is low (with a 25% loading of the nitrophorins during the fourth- to fifth-instar molt). NO loading of the nitrophorins increases to 90% after the molt, concomitant with a large increase in the salivary NADPH diaphorase activity. It is concluded that synthesis of NO occurs within the epithelial cells while the nitrophorins are stored extracellularly. It is hypothesized that the luminally oriented microvilli may serve as a diffusion bridge to direct intracellularly produced NO into the luminal cavity, where the nitrophorins are stored.

Purification, Characterization and cDNA Cloning of a Novel Anticoagulant of the Intrinsic Pathway, (Prolixin-S), from Salivary Glands of the Blood Sucking Bug, Rhodnius prolixus

1996 ◽  
Vol 75 (04) ◽  
pp. 573-577 ◽  
Author(s):  
Jianxin Sun ◽  
Masahiro Yamaguchi ◽  
Masao Yuda ◽  
Ken Miura ◽  
Hiroyuki Takeya ◽  
...  
Keyword(s):  
Salivary Glands ◽  
Protein A ◽  
Gel Filtration ◽  
Specific Inhibitor ◽  
Rhodnius Prolixus ◽  
Amino Acid Sequences ◽  
Factor X ◽  
Blood Sucking ◽  
Red Color ◽  
Absorbance Peak

SummaryThe salivary glands of the blood sucking insect, Rhodnius prolixus, have an anticoagulant, prolixin-S, which was reported as a specific inhibitor of intrinsic coagulant pathway. Prolixin-S was purified from the salivary glands extract of Rhodnius prolixus by gel filtration and anion exchange HPLC by assaying prolongation of activated partial thromboplastin time (APTT). The isolated protein specifically inhibited factor IXa-catalyzed activation of factor X in the presence of Ca2+ and phospholipids irrespective of the presence or absence of factor Villa. The anticoagulant factor had red color and a specific absorbance peak at 402 nm and thus it was identified as a heme protein. A Rhodnius prolixus salivary gland cDNA library was prepared, screened with an antibody against prolixin-S and its complete cDNA sequence was determined. cDNA and deduced amino acid sequences showed that prolixin-S is a novel anticoagulant of 19,922 Da, which has no sequence homology with any other anticoagulant reported so far.

scholarly journals Identification and acitivities of anticoagulants in the salivary glands of the blood sucking kissing bug, Rhodnius prolixus

1996 ◽  
Vol 47 (3) ◽  
pp. 263-272 ◽  
Author(s):  
Masao YUDA ◽  
Jianxin SUN ◽  
Masahiro YAMAGUCHI ◽  
Katsuhiko ANDO ◽  
Yasuo CHINZEI
Keyword(s):  
Salivary Glands ◽  
Rhodnius Prolixus ◽  
Blood Sucking
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