Extremophile

From Proteopedia

(Difference between revisions)
Jump to: navigation, search
Line 8: Line 8:
However, a 3-fold increase in concentration of myoglobin ought to result in a similar fold increase in max time of breath holding, and the researchers determine that body mass also makes a critical contribution to an animal's ability to hold its breath, with the overall equation for the contribution of body mass and myoglobin net charge as follows:
However, a 3-fold increase in concentration of myoglobin ought to result in a similar fold increase in max time of breath holding, and the researchers determine that body mass also makes a critical contribution to an animal's ability to hold its breath, with the overall equation for the contribution of body mass and myoglobin net charge as follows:
 +
log (maximum time underwater) = 0.223*log(body mass) + 0.972*log(myoglobin net charge) + 0.891
log (maximum time underwater) = 0.223*log(body mass) + 0.972*log(myoglobin net charge) + 0.891

Revision as of 18:06, 31 December 2013

Extraordinary Proteins

Life - DNA, Proteins, physiology, behavior, and all - has managed to weather extreme environments - almost every hole we've poked a stick into contains thriving living communities. Proteins are a necessity for living, and therefore tuning protein structures to an extreme environment is of paramount value to an evolving organism seeking an extraordinary niche. In this article we'll present the biophysical strategies apparent from some extreme protein structures.

Positively charged myoglobin allows whales to hold their breath during long dives

Elephants can hold their breath for 2 minutes, but whales can hold their breath for 60 minutes - and they do, migrating underwater around the world. To get a clue as to why whales can hold their breath for so long, several researchers attained tissue samples from hundreds of aquatic and terrestrial mammialian species (mainly from museum collections)[1]. They measured the concentration of myoglobin, the protein that stores oxygen in muscle tissue for times of muscle activity, and also sequenced each specie's myoglobin gene, and used to sequence - as well as eletrophoresis of the protein, when possible - to calculate the net charge of each myoglobin protein. Amazingly they found that independently, aquatic mammals across the mammalian phylogeny had acquired their ability to hold their breath, by increasing the concentration of myoglobin, through increasing the net charge of myoglobin. In real values, typically, terrestrial mammal's myoglobin has a solubility of 20 mg/g tissue ([Sigma Aldrich]) and that is the level of myoglobin found in most terrestrial mammals tissue. But whales and other aquatic mammals far exceed this solubility limit - whales have 70 mg/g - and this overcoming the solubility contrains may be traced back to an increase in the net charge of myoglobin - from around +2 in terrestrial animals to around +4 in aquatic animlals.

However, a 3-fold increase in concentration of myoglobin ought to result in a similar fold increase in max time of breath holding, and the researchers determine that body mass also makes a critical contribution to an animal's ability to hold its breath, with the overall equation for the contribution of body mass and myoglobin net charge as follows:

log (maximum time underwater) = 0.223*log(body mass) + 0.972*log(myoglobin net charge) + 0.891

myoglobin (PDB entry 1mbn)

Drag the structure with the mouse to rotate
  1. ↑ 1.0 1.1 Mirceta S, Signore AV, Burns JM, Cossins AR, Campbell KL, Berenbrink M. Evolution of mammalian diving capacity traced by myoglobin net surface charge. Science. 2013 Jun 14;340(6138):1234192. doi: 10.1126/science.1234192. PMID:23766330 doi:http://dx.doi.org/10.1126/science.1234192
  2. ↑ Brocchieri L. Environmental signatures in proteome properties. Proc Natl Acad Sci U S A. 2004 Jun 1;101(22):8257-8. Epub 2004 May 24. PMID:15159533 doi:http://dx.doi.org/10.1073/pnas.0402797101
  3. ↑ Goh CS, Lan N, Douglas SM, Wu B, Echols N, Smith A, Milburn D, Montelione GT, Zhao H, Gerstein M. Mining the structural genomics pipeline: identification of protein properties that affect high-throughput experimental analysis. J Mol Biol. 2004 Feb 6;336(1):115-30. PMID:14741208 doi:http://dx.doi.org/10.1016/S0022283603014748
Retrieved from "http://52.214.119.220/wiki/index.php/Extremophile"
Personal tools