The role of protein assembly in dynamically tunable bio-optical tissues

Tao, Andrea R.; DeMartini, Daniel G.; Izumi, Michi; Sweeney, Alison; Holt, Anatol W.; Morse, Daniel E.

doi:10.1016/j.biomaterials.2009.10.038

Cited by 93 publications

(208 citation statements)

References 24 publications

Supporting

Mentioning

196

Contrasting

Unclassified

Order By: Relevance

“…Ca 2+ acts as a second messenger, binding calmodulin (24) and activating protein kinases and phosphatases (29). The resulting differential phosphorylation and dephosphorylation of specific reflectins, as observed (13), apparently overcomes Coulombic repulsion, driving the observed condensation of the reflectins to a dense, compressible, hydrogel-like network (26). This condensation of the reflectin proteins, before any change in the dimensions of the Bragg reflector, is first manifested optically as the previously observed increase in the refractive index contrast between the intra-and extralamellar compartments and the consequent onset of bright reflectance, before any progressive shift in reflected wavelength (26).…”

Section: Resultsmentioning

confidence: 83%

“…In this case, we observed significant water expulsion from the dorsal iridocytes, whereas the ventral iridocytes showed relatively poor response compared with the control. Correspondingly, the dorsal iridocytes displayed the most significant photonic response, changing color from the initial nonreflecting state to red and then progressively to blue, whereas the ventral cells showed only small changes (7,21,26). Several important assumptions and approximations are made in analyzing the water exchange experiments of this study.…”

Section: Resultsmentioning

confidence: 97%

See 1 more Smart Citation

Membrane invaginations facilitate reversible water flux driving tunable iridescence in a dynamic biophotonic system

DeMartini

Krogstad

Morse

2013

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

101

132

View full text Add to dashboard Cite

Squids have used their tunable iridescence for camouflage and communication for millions of years; materials scientists have more recently looked to them for inspiration to develop new "biologically inspired" adaptive optics. Iridocyte cells produce iridescence through constructive interference of light with intracellular Bragg reflectors. The cell's dynamic control over the apparent lattice constant and dielectric contrast of these multilayer stacks yields the corresponding optical control of brightness and color across the visible spectrum. Here, we resolve remaining uncertainties in iridocyte cell structure and determine how this unusual morphology enables the cell's tunable reflectance. We show that the plasma membrane periodically invaginates deep into the iridocyte to form a potential Bragg reflector consisting of an array of narrow, parallel channels that segregate the resulting high refractive index, cytoplasmic protein-containing lamellae from the lowindex channels that are continuous with the extracellular space. In response to control by a neurotransmitter, the iridocytes reversibly imbibe or expel water commensurate with changes in reflection intensity and wavelength. These results allow us to propose a comprehensive mechanism of adaptive iridescence in these cells from stimulation to color production. Applications of these findings may contribute to the development of unique classes of tunable photonic materials. Doryteuthis opalescens | iridophore | structural colorA lthough structural color is widespread across both the animal and plant kingdoms (1-4), there are very few cases in which the photonic structures are tunable and adaptive (5-7). Many cephalopods exhibit iridescence, but only a few squid species can tune this iridescence for adaptive camouflage and communication (8,9) by modulating the periodicity of multilayer reflectors (7) in specialized cells classically called iridocytes.[Earlier workers have referred to these cells variously as iridocytes, iridophores, or reflective cells. We use here the unambiguous convention of contemporary cell biology, referring to them as iridocytes (literally "iridescent cells"), with no specific photonic mechanism implied.] For this reason, the tunable photonics of squids have long been a source of intrigue and inspiration to materials scientists (10-12). Although it is known that the neurotransmitter acetylcholine (ACh) activates a signal-transduction cascade to drive the changes in periodicity of the reflectors (7, 13), and the nerve cells delivering this signal recently have been identified (14), details of the molecular mechanisms and cellular architectures governing the biophotonic processes themselves have remained elusive.Morphology of cephalopod iridocytes has traditionally been interrogated by light microscopy ( Fig. 1 A and B) and transmission electron microscopy (TEM) (Fig. 1 C and D), revealing the membrane-bound subcellular lamellae that constitute a Bragg reflector. Whereas these analyses by optical imaging are fundamentally limited because t...

show abstract

Section: Resultsmentioning

confidence: 83%

Section: Resultsmentioning

confidence: 97%

Membrane invaginations facilitate reversible water flux driving tunable iridescence in a dynamic biophotonic system

DeMartini

Krogstad

Morse

2013

Proc. Natl. Acad. Sci. U.S.A.

Self Cite

101

132

View full text Add to dashboard Cite

show abstract

“…In the tissues of these animals, various nano and microscale components play roles in generating distinct colours and achieving rapid colour changes 4,5 . Inspired by nature, sensors are being developed that change colour in response to target chemicals by employing biomimetic structures and mechanisms.…”

mentioning

confidence: 99%

Biomimetic virus-based colourimetric sensors

et al. 2014

View full text Add to dashboard Cite

Many materials in nature change colours in response to stimuli, making them attractive for use as sensor platform. However, both natural materials and their synthetic analogues lack selectivity towards specific chemicals, and introducing such selectivity remains a challenge. Here we report the self-assembly of genetically engineered viruses (M13 phage) into targetspecific, colourimetric biosensors. The sensors are composed of phage-bundle nanostructures and exhibit viewing-angle independent colour, similar to collagen structures in turkey skin. On exposure to various volatile organic chemicals, the structures rapidly swell and undergo distinct colour changes. Furthermore, sensors composed of phage displaying trinitrotoluene (TNT)-binding peptide motifs identified from a phage display selectively distinguish TNT down to 300 p.p.b. over similarly structured chemicals. Our tunable, colourimetric sensors can be useful for the detection of a variety of harmful toxicants and pathogens to protect human health and national security.

show abstract

“…Recently, our group discovered that reflectin, a structural protein that plays a key role in the color-changing abilities of cephalopods, [16][17][18][19][20] is an effective proton conducting material. 21 This finding enabled the fabrication of protein-based protonic transistors with excellent figures of merit, including a proton mobility (µ H+ ) of ∼7.3 × 10 −3 cm 2 V −1 s −1 .…”

mentioning

confidence: 99%

Protonic transistors from thin reflectin films

Ordinario¹,

Phan²,

Jocson³

et al. 2014

APL Materials

View full text Add to dashboard Cite

Ionic transistors from organic and biological materials hold great promise for bioelectronics applications. Thus, much research effort has focused on optimizing the performance of these devices. Herein, we experimentally validate a straightforward strategy for enhancing the high to low current ratios of protein-based protonic transistors. Upon reducing the thickness of the transistors’ active layers, we increase their high to low current ratios 2-fold while leaving the other figures of merit unchanged. The measured ratio of 3.3 is comparable to the best values found for analogous devices. These findings underscore the importance of the active layer geometry for optimum protonic transistor functionality.

show abstract

The role of protein assembly in dynamically tunable bio-optical tissues

Cited by 93 publications

References 24 publications

Membrane invaginations facilitate reversible water flux driving tunable iridescence in a dynamic biophotonic system

Membrane invaginations facilitate reversible water flux driving tunable iridescence in a dynamic biophotonic system

Biomimetic virus-based colourimetric sensors

Protonic transistors from thin reflectin films

Contact Info

Product

Resources

About