What is meant by Chromoprotein?
Definition of chromoprotein : any of various proteins (such as hemoglobins, carotenoids, or flavoproteins) having a pigment as a prosthetic group.
Is chlorophyll a Chromoprotein?
Pigmentation. The photosynthetic pigments of cyanobacteria include chlorophyll a, β-carotene, zeaxanthin, echinenone, myxoxanthophyll, and other xanthophylls in addition to an array of water soluble chromoproteins, organized in the phycobilisomes.
Is the example of chromoproteins?
A chromoprotein is a conjugated protein that contains a pigmented prosthetic group. A common example is haemoglobin, which contains a heme cofactor, which is the iron-containing molecule that makes oxygenated blood appear red.
What is an example of metalloprotein?
An example of metalloprotein is Ceruloplasmin.
Are all phytochromes Photoreversible?
Photoreversibility occurs because phytochromes exist as two distinct but photoreversible forms in vivo: the R light-absorbing form (Pr) and the FR light-absorbing form (Pfr).
What is PFR and PR?
Phytochromes are red-light photoreceptors that undergo reversible photoconversion between a red-light-absorbing state (Pr) and a far-red-light-absorbing state (Pfr), and thereby they regulate a wide range of physiological responses in plants, fungi, and photosynthetic bacteria (1–5).
How do chromoproteins work?
Because chromoproteins absorb visible light and give off color in ambient light, it gives scientists the ability for instrument-free detection. Unlike fluorescence or luminescence, which require UV lamps, fluorometers, or luminometers, chromoprotein detection can be done by the naked eye.
What are phytochromes examples?
Hence maize, for example, has six phytochromes – phyA1, phyA2, phyB1, phyB2, phyC1 and phyC2. While all these phytochromes have significantly different protein components, they all use phytochromobilin as their light-absorbing chromophore.
What do cryptochromes do?
Cryptochromes (CRY) are photosensory receptors that regulate growth and development in plants and the circadian clock in plants and animals [1, 2]. Plant cryptochromes are best studied in Arabidopsis (Arabidopsis thaliana).
What is an example of phosphoprotein?
Phosphoproteins are conjugate proteins, post-translationally modified by the attachment of phosphate group. Common examples of naturally occurring phosphoproteins are milk protein casein and ovo-vitellin of egg yolk.
What is the meaning of metalloproteins?
The term metalloprotein is used to define a large group of proteins containing one or more atoms of metal bound to specific sites in the polypeptide chain.
What are the examples of metalloenzymes?
Other metalloenzymes
| Ion | Examples of enzymes containing this ion |
|---|---|
| Nickel | Urease Hydrogenase Methyl-coenzyme M reductase (MCR) |
| Copper | Cytochrome oxidase Laccase Nitrous-oxide reductase Nitrite reductase |
| Zinc | Alcohol dehydrogenase Carboxypeptidase Aminopeptidase Beta amyloid |
| Cadmium | Metallothionein Thiolate proteins |
What are Metalloenzymes give example?
copper (Cu) are crucial in metalloenzymes—for example, cytochrome C, in which the sulfur of methionine is coordinated to the iron in heme; the iron-sulfur proteins, in which cysteine sulfur is bound to iron; and molybdenum-containing enzymes, some of which involve dithiolate (two-sulfur) cofactors.
How many phytochromes are there?
five phytochromes
The Phytochrome Gene Family In Arabidopsis thaliana, there are five phytochromes, designated phytochrome A (phyA) to phyE. They are encoded by five distinct members of the phytochrome gene family and are classified into two groups according to their stability in light (Sharrock and Quail, 1989).
What is a a chromoprotein?
A chromoprotein is a conjugated protein that contains a pigmented prosthetic group (or cofactor). A common example is haemoglobin, which contains a heme cofactor, which is the iron -containing molecule that makes oxygenated blood appear red.
What is the absorption band of a chromoprotein?
Chromoproteins are characterized by an electronic absorption band in the near-UV, visible or near-IR spectral range. These bands may arise from π → π* transitions of prosthetic groups or from charge-transfer transitions of specifically bound transition metal ions.
Is hemoglobin a phototropin or a phytochrome?
In hemoglobin there exists a chromoprotein ( tetramer MW:4 x 16.125 =64.500), namely heme, consisting of Fe++ four pyrrol rings. A single chromoprotein can act as both a phytochrome and a phototropin due to the presence and processing of multiple chromophores.
What is the chromophore derived from?
The chromophore is derived from Glu-63, Tyr-64 and Gly-65 and the phenolic group of Tyr-64 plays a vital role in the formation of a conjugated system with the imidazolidone moiety resulting a high absorbance in the absorption spectrum of chromoprotein in the excited state.