Binding of radio-iodinated gonadotropin to the ovary of exotic carp (Cyprinus carpio Lin.)

Heterologous murrel gonadotropic hormone (m-GtH) binds to common carp oocyte plasma membrane and enhances steroid secretion. With increasing concentration of radio-labelled hormone the receptor binding is also found to increase linearly up to a certain concentration and then decrease. The [¹²⁵I] murrel GtH binding characteristics to a preparation of common carp ovarian plasma membrane shows saturability with high affinity. Scat chard plot analysis gave dissociation constant (Kd) of 0.81 X 10(super -9) M and maximum binding capacity (MBC) of 22.05 f mole/mg protein.

Sulfide binding characteristics of blood serum in Calyptogena pacifica and Vesicomya gigas

The sulfide binding characteristics of blood serum were studied in vitro in two deep-sea vesicomyid clams, Calyptogena pacifica and Vesicomya gigas. Both the C. pacifica and the V. gigas serum concentrated sulfide at least an order of magnitude above ambient levels. V. gigas accumulated sulfide faster than C. pacifica, reaching saturation at 5000 M after an hour. C. pacifica bound sulfide at half the rate of V. gigas, reaching saturation in about two hours at a substantially higher concentration of sulfide. The observed distribution of the animals near cold seeps in the Monterey Submarine Canyon can be explained by their different sulfide binding abilities. The hypothesis that cold seeps are actually much more unstable sources of sulfide than previously assumed is explored.

Embankment damaging marine organisms and their control measures using calcium carbide

Five species of crabs and three species of fishes were the main marine organisms found damaging embankments owing to their burrowing nature. Among crabs, Scylla serrata was in the highest percentage, while among fishes, Boleopthalamus dussumieri was recorded in maximum percentage calcium carbide 10-15 per burrow was effective in eradicating the crabs.

Cloning and characterization of a blood coagulation factor IX-binding protein from the venom of Trimeresurus stejnegeri

A blood coagulation factor IX-binding protein (TSV-FIX-BP) was isolated from the snake venom of Trimeresurus stejnegeri. On SDS-polyacrylamide gel electrophoresis, TSV-FIX-BP showed a single band with an apparent molecular weight of 23,000 under non-reducing conditions. and two distinct bands with apparent molecular weights of 14,800 and 14,000 under reducing conditions. cDNA clones containing the coding sequences of TSV-FIX-BP were isolated and sequenced to determine the structure of the precusors of TSV-FIX-BP subunits. The deduced amino acid sequences of two subunits of TSV-FIX-BP were confirmed by N-terminal protein sequencing and trypsin-digested peptide mass fingerprinting. TSV-FIX-BP was a nonenzymatic C-type lectin-like anti-coagulant. The anti-coagulant activity of TSV-FIX-BP was mainly caused by its dose dependent interaction with blood coagulation factor IX but not with blood coagulation factor X. (C) 2003 Elsevier Science Ltd. All rights reserved.

Molecular cloning and characterization of a platelet glycoprotein Ib-binding protein from the venom of Trimeresurus stejnegeri

A platelet glycoprotein Ib-binding protein, termed TSV-GPIb-BP, was isolated from the venom of Trimeresurus stejnegeri. On SDS-polyacrylamide gel electrophoresis, TSV-GPIb-BP showed a single band with an apparent molecular weight of 28,000 and two distinct bands with apparent molecular weights of 16,000 and 15,000 under non-reducing and reducing conditions, respectively. cDNA clones containing the coding sequences for both TSV-GPIb-BP subunits were isolated and sequenced. The deduced amino acid sequences of TSV-GPIb-BP subunits were confirmed by N-terminal protein sequencing and trypsin-digested peptide mass fingerprinting. Interestingly, the a subunit of TSV-GPIb-BP is identical to that of alboaggregin-B, and the sequence identity of their beta subunits is 94.3%. TSV-GPIb-BP inhibited ristocetin-induced human platelet agglutination in platelet-rich plasma under lower dosages (<5 mug/ml). On the other hand, it directly aggregated washed human platelets in the absence of additional Ca2+ or any other cofactors under higher dosages (>5 mug/ml). This platelet aggregation activity was dose-dependently inhibited by specific GPIbalpha antibodies, but not by those antibodies against platelet GPIa, GPIIa, GPIIb and GPIIIa. (C) 2003 Elsevier Science Ltd. All rights reserved.

A novel disintegrin, jerdonatin, inhibits platelet aggregation and sperm-egg binding

A novel disintegrin, jerdonatin, was purified to homogeneity from Trimeresurus jerdonii venom by gel filtration and reversed-phase high-pressure liquid chromatography. We isolated the cDNA encoding jerdonatin from the snake venom gland. Jerdonatin cDNA precursor,;encoded pre-peptide, metalloprotease and disintegrin domain. Jerdonatin is composed of 72 amino acid residues including 12 cysteines and the tripeptide sequence Arg-Gly-Asp (RGD), a well-known characteristic of the disintegrin family. Molecular mass of jerdonatin was determined to be 8011 Da by matrix-assisted laser desorption ionization time of flight mass spectrometry (MALDI-TOF-MS). Jerdonatin inhibited ADP- and collagen-induced human platelet aggregation with IC50 of 123 and 135 nM, respectively. We also investigated the effect of jerdonatin on the binding of B6D2F1 hybrid mice spermatozoa to mice zona-free eggs and their subsequent fusion. Jerdonatin significantly inhibited sperm-egg binding in a concentration-dependent manner, but had no effect on the fusion of sperm-egg. These results indicate that integrins on the egg play a role in mammalian fertilization. (C) 2004 Elsevier Inc. All rights reserved.

Probing small molecule binding to amyloid fibrils.

Much effort has focussed in recent years on probing the interactions of small molecules with amyloid fibrils and other protein aggregates. Understanding and control of such interactions are important for the development of diagnostic and therapeutic strategies in situations where protein aggregation is associated with disease. In this perspective article we give an overview over the toolbox of biophysical methods for the study of such amyloid-small molecule interactions. We discuss in detail two recently developed techniques within this framework: linear dichroism, a promising extension of the more traditional spectroscopic techniques, and biosensing methods, where surface-bound amyloid fibrils are exposed to solutions of small molecules. Both techniques rely on the measurement of physical properties that are very directly linked to the binding of small molecules to amyloid aggregates and therefore provide an attractive route to probe these important interactions.

Is there a close relationship between synonymous codon bias and codon-anticodon binding strength in human genes?

Synonymous codon bias has been examined in 78 human genes (19967 codons) and measured by relative synonymous codon usage (RSCU). Relative frequencies of all kinds of dinucleotides in 2,3 or 3,4 codon positions have been calculated, and codon-anticodon bin

Aniracetam restores the effects of amyloid-beta protein or ageing on membrane fluidity and intracellular calcium concentration in mice synaptosomes

In the present study, we observed the in vitro effect of aniracetam on membrane fluidity and free calcium concentrations (Ca(2+)i) of frontal cortical (FC) and hippocampal (HP) synaptosomes of aged mice and young mice treated with amyloid-beta protein (A

The water stability of shrimp diets with various polysaccharides as a binding agent

The water stability of shrimp (Penaeus monodon) diets with various polysaccharides as binding agents were tested without steaming. The diet with alginate showed the best water stability and did not completely disintegrate in 24 hours. However, the use of alginate is dependent on cost and availability, so alternate choices may be a combination of sago palm starch and wheat flour or glutinous rice flour.

Symmetrical 1-pyrrolidineacetamide showing anti-HIV activity through a new binding site on HIV-1 integrase

Aim: To characterize the functional and pharmacological features of a symmetrical 1-pyrrolidineacetamide, N,N'-(methylene-di-4,1-phenylene) bis-1-pyrrolidineacetamide, as a new anti-HIV compound which could competitively inhibit HIV-1 integrase (IN) bindi

Enrichment of rotifer Brachionus rotundiformis with calcium

Possibility of enrichment of rotifer (Brachionus rotondiformis) with calcium (Ca) for feeding the fish fry was investigated. Rotifer was kept for 24 h with aeration in normal seawater (Treatment 1), seawater with 400 mg/l supplemental Ca from Ca-lactate (Treatment 2) and seawater with 400 mg/l supplemental Ca from Ca-chloride (Treatment 3). After the experimental period, Ca contents of rotifer were 0.20, 0.29 and 0.39% of dry weight in T-1, T-2 and T-3, respectively. Ca content of media did not affect phosphorus, zinc and manganese contents of rotifer. Results revealed that rotifer can be enriched with Ca for feeding fish fry and Ca-chloride might be a better source for Ca enrichment.

Calcium-permeable acid-sensing ion channel is a molecular target of the neurotoxic metal ion lead

Acid-sensing ion channels (ASICs) are emerging as fundamental players in the regulation of neural plasticity and in pathological conditions. Here we showed that lead (Pb2+), a well known neurotoxic metal ion, reversibly and concentration-dependently inhib

Necessity of dietary calcium supplement in file fish (Monacanthus cirrhifer)

File fish, Monacanthus cirrhifer, juveniles with initial mean body weight of 0.27g were fed purified diets with or without calcium (Ca) supplement for 10 weeks at a water temperature of 27.0±1.4°C. Growth was significantly low in fish fed diet without Ca supplement than fish fed diet with Ca supplement. Feed efficiency and condition of fish were also significantly decreased in absence of a dietary Ca supplementation, Minerals contents of bone were similar in both the treatment groups and did not appear as a suitable indicator of Ca requirement. It appeared that Ca supplement to the purified diet is necessary for file fish for their proper growth and feed utilization.