Have you ever wondered how those lazy small snails catch their prey?
Well, here is how they do...
Cone snails are some of the most amazing creatures in the world of marine animals. Very little is known about them. They have a mind-blowing variety of toxins. These toxins are usually about 12 to 30 amino acid residues long with unusually large numbers of disulphide bridges. The toxins are so diverse that no two species of cone snails have same toxins. Even the composition of different toxins in their venom differs.
The pharmaceutical potential of some of these toxins have been identified and are in clinical and preclinical studies. These toxins can be used in the treatment of various diseases, from hypertension to depression.
Showing posts with label toxin. Show all posts
Showing posts with label toxin. Show all posts
Saturday
Thursday
Toxin - Nanoparticle Combine Defeats Cancer
Diptheria toxin is a protein secreted by Corynebacterium diphtheriae.
The protein has three domains - A, B and T. The B domain is believed to be responsible for recognizing the cell surface receptors. The toxin is found to show affinity for heparin binding epidermal like growth factor like precursors, which are found on the cell surface. T domain aids the protein to gain entry into the cell.
The A chain has the enzymatic activity. It catalyzes the ADP ribosylation of eukaryotic aminoacyl transferase II. This prevents protein biosynthesis in the cells leading to cell death.
The diphtheria toxin A (DT - A) chain's toxic properties can be exploited by properly guiding them to the cells that need to be killed.
This is exactly what the researchers have done using nanotechnology.
A nanoparticulate system made of Poly(beta amino ester) polymer and poly( butane diol diacrylate co amino pentanol) was used to deliver the diphtheria toxin A (DT - A) gene. This gene is linked to a regulatory sequence that gets activated only in prostate cancer cells. While the specificity is taken care of by the gene regulator, safe delivery of the toxin into these cells is the responsibility of the nanoparticulate system. Now, the diphtheria toxin does the rest.
Studies in the laboratory show promising results. Well, I guess we can expect efficient nano based injectable or ingestible drugs to treat cancer in the near future.
The protein has three domains - A, B and T. The B domain is believed to be responsible for recognizing the cell surface receptors. The toxin is found to show affinity for heparin binding epidermal like growth factor like precursors, which are found on the cell surface. T domain aids the protein to gain entry into the cell.
The A chain has the enzymatic activity. It catalyzes the ADP ribosylation of eukaryotic aminoacyl transferase II. This prevents protein biosynthesis in the cells leading to cell death.
The diphtheria toxin A (DT - A) chain's toxic properties can be exploited by properly guiding them to the cells that need to be killed.
This is exactly what the researchers have done using nanotechnology.
A nanoparticulate system made of Poly(beta amino ester) polymer and poly( butane diol diacrylate co amino pentanol) was used to deliver the diphtheria toxin A (DT - A) gene. This gene is linked to a regulatory sequence that gets activated only in prostate cancer cells. While the specificity is taken care of by the gene regulator, safe delivery of the toxin into these cells is the responsibility of the nanoparticulate system. Now, the diphtheria toxin does the rest.
Studies in the laboratory show promising results. Well, I guess we can expect efficient nano based injectable or ingestible drugs to treat cancer in the near future.
Wednesday
Now Polonium...... then Ricin!!!!
Alexander Litvinenko was assasinated in london recently. He was poisoned by radioactive Polonium 210.
Alexander Litvinenko had earlier accused the Kremblin of involvement in the death of about 300 people in Russia in 1999.
This is not the first time Russia stands accused of silencing its critics abroad through assassination.
In 1978, Georgi Markov, a communist defector was killed by a tiny pellet of a substance called Ricin.
He was Bulgarian. He took refuge in London and worked as a broadcaster in BBC. He criticized the Bulgarian communist regime. It is believed by many that this lead Bulgarian government to seek KGB's assistance in silencing him.
On September 7, 1978 he developed high fever and was admitted to the hospital. He died in three days. The cause of death was not clear. Before his death, he recalled an incident, which was key to unraveling this successful assassination attempt.
He was waiting at the bus stop near the Water Loo bridge when he felt a stinging pain in his legs. He turned and saw a man pick up his umbrella and apologize. He (probably) ignored it. But, by the time he realized that it was no accident, it was too late.
He died on September 11, 1978. During his postmortem investigation, forensic pathologists discovered a spherical pellet the size of a tiny pin-head. The pellet had two holes the size of 0.35mm drilled into it. Traces of Ricin was was found in those holes.
Ricin is a toxin. According to FBI, it is one of three most dangerous substances on Earth. It is perhaps the most easily available bioweapon.
Ricin is a protein found in the castor plant (Ricinus communis), the one from which we get Castor oil. This grows in almost all tropical countries. The toxic effects of castor seeds are well known.
Ricin is a very powerful cytotoxin. It belongs to a group of toxins called Ribosome Inactivation Proteins. Ricin is a Type 2 RIP. That is it has 2 poypeptide chains - one to bind to the cell membrane and the other to enter the cell and inactivate the ribosome.
The RTA chain of this heterodimeric protein gains entry into the cell with the help of RTB chain. Once inside, the RTA (a 267 residue long polypeptide) exhibits its N - glycosidase activity by removing A4324 in the 28S rRNA of 60 S subunit of the ribosome. Removal of this prevents the binding of elongation factors. This halts protein synthesis. The cell ultimately dies.
The toxic effects of this protein may develop as soon as within 2 hours of exposure. The symptoms of the ricin poisoning varies with the system that is exposed. It is quite difficult to zero in on the toxin very easily.
There is no vaccine for the protein. There is no direct cure. It is easily available and it is not that difficult to spot Castor plant in any country!!!
All these make it the most efficient bioweapon candidate. And, the 'umbrella murder' Georgi Markov brought the tropical toxin to the lime-light.
Alexander Litvinenko had earlier accused the Kremblin of involvement in the death of about 300 people in Russia in 1999.
This is not the first time Russia stands accused of silencing its critics abroad through assassination.
In 1978, Georgi Markov, a communist defector was killed by a tiny pellet of a substance called Ricin.
He was Bulgarian. He took refuge in London and worked as a broadcaster in BBC. He criticized the Bulgarian communist regime. It is believed by many that this lead Bulgarian government to seek KGB's assistance in silencing him.
On September 7, 1978 he developed high fever and was admitted to the hospital. He died in three days. The cause of death was not clear. Before his death, he recalled an incident, which was key to unraveling this successful assassination attempt.
He was waiting at the bus stop near the Water Loo bridge when he felt a stinging pain in his legs. He turned and saw a man pick up his umbrella and apologize. He (probably) ignored it. But, by the time he realized that it was no accident, it was too late.
He died on September 11, 1978. During his postmortem investigation, forensic pathologists discovered a spherical pellet the size of a tiny pin-head. The pellet had two holes the size of 0.35mm drilled into it. Traces of Ricin was was found in those holes.
Ricin is a toxin. According to FBI, it is one of three most dangerous substances on Earth. It is perhaps the most easily available bioweapon.
Ricin is a protein found in the castor plant (Ricinus communis), the one from which we get Castor oil. This grows in almost all tropical countries. The toxic effects of castor seeds are well known.
Ricin is a very powerful cytotoxin. It belongs to a group of toxins called Ribosome Inactivation Proteins. Ricin is a Type 2 RIP. That is it has 2 poypeptide chains - one to bind to the cell membrane and the other to enter the cell and inactivate the ribosome.
The RTA chain of this heterodimeric protein gains entry into the cell with the help of RTB chain. Once inside, the RTA (a 267 residue long polypeptide) exhibits its N - glycosidase activity by removing A4324 in the 28S rRNA of 60 S subunit of the ribosome. Removal of this prevents the binding of elongation factors. This halts protein synthesis. The cell ultimately dies.
The toxic effects of this protein may develop as soon as within 2 hours of exposure. The symptoms of the ricin poisoning varies with the system that is exposed. It is quite difficult to zero in on the toxin very easily.
There is no vaccine for the protein. There is no direct cure. It is easily available and it is not that difficult to spot Castor plant in any country!!!
All these make it the most efficient bioweapon candidate. And, the 'umbrella murder' Georgi Markov brought the tropical toxin to the lime-light.
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