Chromoprotein
Achromoproteinis a conjugated protein that contains apigmentedprosthetic group(or cofactor). A common example ishaemoglobin,which contains ahemecofactor, which is theiron-containing molecule that makesoxygenatedblood appear red. Other examples of chromoproteins include otherhemochromes,cytochromes,phytochromesandflavoproteins.[1]
In hemoglobin there exists a chromoprotein (tetramerMW:4 x 16.125 =64.500), namely heme, consisting of Fe++ fourpyrrolrings.
A single chromoprotein can act as both aphytochromeand aphototropindue to the presence and processing of multiple chromophores. Phytochrome in ferns containsPHY3which contains an unusual photoreceptor with a dual-channel possessing both phytochrome (red-light sensing) and phototropin (blue-light sensing) and this helps the growth of fern plants at low sunlight.[2]
TheGFPprotein family includes both fluorescent proteins and non-fluorescent chromoproteins. Through mutagenesis or irradiation, the non-fluorescent chromoproteins can be converted to fluorescent chromoproteins.[3]An example of such converted chromoprotein is "kindling fluorescent proteins" or KFP1 which was converted from a mutated non-fluorescentAnemonia sulcatachromoprotein to a fluorescent chromoprotein.[4]
Sea anemones contain purple chromoprotein shCP with its GFP-like chromophore in thetrans-conformation.The chromophore is derived from Glu-63, Tyr-64 and Gly-65 and thephenolic groupof Tyr-64 plays a vital role in the formation of aconjugated systemwith theimidazolidonemoiety resulting a high absorbance in theabsorption spectrumof chromoprotein in the excited state. The replacement of Tyrosine with other amino acids leads to the alteration of optical and non-planer properties of the chromoprotein. Fluorescent proteins such as anthrozoa chromoproteins emit long wavelengths[4]
14 chromoproteins were engineered to be expressed inE. coliforsynthetic biology.[5]However, chromoproteins bring high toxicities to theirE. colihosts, resulting in the loss of colors. mRFP1, the monomericred fluorescent protein,[6]which also displays distinguishable color under ambient light, was found to be less toxic.[7]Color-changing mutagenesis on amino acids 64–65 of the mRFP1 fluorophore was done to acquire different colors.
References
[edit]- ^ Fearon WR (1940).An Introduction to Biochemistry.Elsevier. p. 131.ISBN9781483225395.
- ^Kanegae T, Hayashida E, Kuramoto C, Wada M (November 2006)."A single chromoprotein with triple chromophores acts as both a phytochrome and a phototropin".Proceedings of the National Academy of Sciences of the United States of America.103(47): 17997–18001.Bibcode:2006PNAS..10317997K.doi:10.1073/pnas.0603569103.PMC1693861.PMID17093054.
- ^Zagranichny VE, Rudenko NV, Gorokhovatsky AY, Zakharov MV, Balashova TA, Arseniev AS (October 2004). "Traditional GFP-type cyclization and unexpected fragmentation site in a purple chromoprotein from Anemonia sulcata, asFP595".Biochemistry.43(42): 13598–13603.doi:10.1021/bi0488247.PMID15491166.
- ^abChang HY, Ko TP, Chang YC, Huang KF, Lin CY, Chou HY, et al. (June 2019). "Crystal structure of the blue fluorescent protein with a Leu-Leu-Gly tri-peptide chromophore derived from the purple chromoprotein of Stichodactyla haddoni".International Journal of Biological Macromolecules.130:675–684.doi:10.1016/j.ijbiomac.2019.02.138.PMID30836182.S2CID73497504.
- ^Liljeruhm J, Funk SK, Tietscher S, Edlund AD, Jamal S, Wistrand-Yuen P, et al. (2018-05-10)."Engineering a palette of eukaryotic chromoproteins for bacterial synthetic biology".Journal of Biological Engineering.12(1): 8.doi:10.1186/s13036-018-0100-0.PMC5946454.PMID29760772.
- ^Campbell RE, Tour O, Palmer AE, Steinbach PA, Baird GS, Zacharias DA, Tsien RY (June 2002)."A monomeric red fluorescent protein".Proceedings of the National Academy of Sciences of the United States of America.99(12): 7877–82.Bibcode:2002PNAS...99.7877C.doi:10.1073/pnas.082243699.PMC122988.PMID12060735.
- ^Bao L, Menon PN, Liljeruhm J, Forster AC (December 2020)."Overcoming chromoprotein limitations by engineering a red fluorescent protein".Analytical Biochemistry.611:113936.doi:10.1016/j.ab.2020.113936.PMID32891596.S2CID221523489.