Cyanide is known to be one of the most toxic substances
present in a wide variety of food materials that are consumed by
One of the cyanide detoxifying enzymes is 3-mercaptopyruvate
sulfurtransferase (3-MST). Indeed, recent studies have clearly
shown that 3-MST is involved in the detoxification of cyanide
larva feeds on dead, decayed and living plants, wood and palm.
Plants are known to contain cyanide as a defence mechanism for
intruding/pesting organisms. Thus, for rhinoceros
larva to be able to live on plants, it must have possessed a cyanide-detoxifying enzyme.
3-MST, a cyanide-detoxifying enzyme was purified from Rhinoceros
larva in this work.
The 3-MST enzyme was isolated from the gut of Oryctes rhinoceros
larvae and purified using Ammonium Sulphate Precipitation,
Bio-Gel-P-100 Gel Filtration Chromatography and Reactive Blue-2-Agarose
The specific activity of the enzyme was 0.22U/mg.
The presence of this enzyme could be exploited by including it in the
diet of animals which would serve as a source of protein and
3-MST. Perhaps, these rhinoceros
larva could be introduced on
farmland with contaminated soil whereby they will process the dead roots
and plants into soil thereby providing more space and manure for plants
to grow healthy.
One of the major metabolic enzymes that have gained so much interest
of scientists is 3-Mercaptopyruvate sulfurtransferase (3-MST). This
enzyme occurs widely in nature (Bordo, 2002 and Jarabak, 1981).
It has been reported in several organisms ranging from humans
to rats,fishes and insects. It is a mitochondrial enzyme which has been
concerned in the detoxification of cyanide, a potent toxin of the
mitochondrial respiratory chain (Nelson et al., 2000).
Among the several metabolic enzymes that carry out xenobiotic
detoxification, 3-mercaptopyruvate sulfurtransferase is of utmost
3-mercaptopyruvate sulfurtransferase functions in the
detoxifications of cyanide; mediation of sulfur ion transfer to cyanide
or to other thiol compounds.(Vanden et al., 1967). It is also
required for the biosynthesis of thiosulfate. In combination with
cysteine aminotransferase, it contributes to the catabolism of cysteine
and it is important in generating hydrogen sulphide in the brain, retina
and vascular endothelial cells (Shibuya et al., 2009). It also
acquired different functions such as a redox regulation
(maintenance of cellular redox homeostasis) and defense against
oxidative stress, in the atmosphere under oxidizing conditions
Nagahara et al (2005).
Hydrogen sulphide (H2S) is an important synaptic modulator,
signalling molecule, smooth muscle contractor and neuroprotectant
(Hosoki et al., 1997).
Its production by the 3-mercaptopyruvate sulfurtransferase and
cysteine aminotransferase pathways is regulated by calcium ions (Hosoki et al., 1997).
Organisms that are exposed to cyanide poisoning usually
have this enzyme in them. This could be in food as in the
cyanogenic glucosides being consumed. It has been studied from variety
of sources, which include bacteria,yeasts, plants, and animals (Marcus
Cyanide could be released into the bark of trees as a defence mechanism.
There are array of defensive compounds that make their parts (leaves, flowers, stems, roots and fruits) distasteful or poisonous to predators. In response,
however, the animals that feed on them have evolved over
successive generations a range of measures to overcome these compounds
and can eat the plant safely. The tree trunk offers a clear
example of the variety of defences available to plants (Marcus
Oryctes rhinoceros larva is one of the organisms that are also exposed to cyanide toxicity because of the environment they are found.