PEMF, green light, nitrate reductase

Nitrate reductase is a target of PEMF. This same enzyme absorbs in the green region of the visible spectrum that some biohackers like to use for healthy skin. .Zeemi 2016 demonstrated that 538 nm green/yellow light resulted in maximal E coli growth reduction. Giordani & Buc 2004 demonstrated a 560 nm absorption band in E coli nitrite reductase sensitive to oxidation and reduction and a 530 nm subpeak. Fojt 2005 demonstrated that 50 Hz PEMF can muck up the nitrate reduction electron transport that some bacteria use to make ATP. Jepson 2007 published a very biophysical paper showing response of E coli nitrate reductase electrons to kHz PEMF using a technique called Electron Paramagnetic Resonance (EPR). The featured image of this post was adapted from the nitrate reductase redox cycle, Tunney 3003 Think about the molybdenum functional groups absorbing green light and maybe very low frequency PEMF as the bacterium tries to make ATP by anaerobic respiration.

An ode to previous Staph aureus posts

This post is also about 530 nm green light, a perfect wavelength for penetrating the outer surface of the skin, but not much deeper. This brings us to the Staph aureus and atopic dermatitis post that PEMF might be a harmless thing to test on atopic dermatitis. Staph aureus metabolism is a hairy, scary biochemical post that deep dives into 530 and 560 nm green light absorbing nitrate reductase being part of this important dermal pathogen. What is true for E coli in this post may also be true for Staph aureus.

Visible light killing of E coli Azeemi 20016

Most of the authors of Azeemi 2016 come from University of Lahorei n Lahore, Pakistan the basic premise was to isolate E coli from six urinary tract infections. These isolates were exposed to visible light while in a standard culture medium called Luria Broth, LB for short. Growth rates were measured by optical density, (cloudiness) and correlated with colony forming units. Scanning electron microscopy was used to assess morphological changes.

Samina Azeemi has a long lecture and publication record on the use of visible light’s interaction with biological systems and its use to treat diseases

color	Dominant wavelength	Hue	Purity (%)	Transmission (%)	#colonies	SEM link
Purple	464	Violet	36%	32%	150	464 nm
Blue	483	Blue Green	52%	52%	300	453 nm
Green	538	Greenish Yellow	15%	37%	10	538 nm
Yellow	590	Reddish Yellow	40%	82%	90	590 nm
Orange	610	Orange	43%	47%	200	610 nm
Red	644	Red	41%	51%	160	644 nm

Azeemi measured the penetration of various colors of light into the LB broth as a control. like everything we see, BL broth appears to have color because because of wavelengths of visible light NOT absorbed.

Control E coli rods have a slight bifurcation through the center. Visible light exposure changes this morphology.

Azeeni 2016 did not identify the mechanism behind E coli responding to visible light. Central to her work is the concept is the notion that biological enzymes absorb visible light thereby affecting their function The following paper does not prove that green/yellow light affects the function of E coli nitrate reductase. It does prove that changes in electron flow affect its absorption of 560 nm green/yellow light.

Electron flow, E coli nitrate reductase Giordani & Buc 2004

In 2004 Giordani and Buc were simply testing the hypothesis that natural and artificial sources of electrons and protons could could enter E coli nitrate reductase at various different functional groups. These bugs use nitrate rather than O₂ as their terminal electron acceptor. We mammals use ubiquinone (CoEnzyme Q) as our electron donor. Many red light biohackers like to cite evidence that cytochrome C oxidase absorbs in the red region. These scientists were not interested in biohacking but they were using changes in aborbance as evidence of successful transfer of an electron to a transport protein.

1. dithionite
2. menadiol
3. duroquinol.
4. a strain of Ecoli lacking nitrate reductase (LCB 2048) and dithionite as reductant.

We will not get into the bigger picture of their study in this post. Take a look at the figures with the above numbering. Note the change in absorbances used in green light therapy!

Summary of 560 nm findings

• Figure 1, Note the green peak at 530 nm as well as 560 nm.
• Figure 2 Using the 560 nm spectra changes, the the ability of electron donors to achieve the reduced state was tested..
• Figure 3 Two different electron donors are shown, only one changes the absorbance at 560nm. The smaller peak at 530 nm was not reported.

There are two other figures, but they are irrelevant to the point of combining green light with PEMF.

Functional groups shuttle electrons in E coli nitrate reductase

Proof that PEMF can muck up the flow of electron Fojt 2005

Fojt 2005 exposed Paracoccus denitrificans to 50 Hz 10 mT PEMF for 24 min. According to Wikipedia authors P dnitrificans reduces nitrate to nitrite, nitric oxide and nitrous oxide. Much of the discussion of this microbe on Wikipedia suggests unusual metabolism. This paper is extremely biophysical. I’ve expended a lot of effort trying to understand how the authors arrived at this conclusion. The average biohacker might want to skip to the next section.

What is reduction?

• “Reduction” in this discussion means, gain of electrons and/or H⁺. In our UniProt example the H⁺ comes from a generic quinol. It could be natural or synthetic.
• Nitrate reductase is the most important electron acceptor for durohydroquinone, a synthetic version of natural ubiquinol.
• The enzyme nitrate reductase is merely a catalyst transferring those H⁺ and electrons to nitrate which rearranges to nitrite and water.
• Note that we aerobes use O₂ as our terminal acceptor of H⁺ and electrons giving H₂O as the product. The above reaction is an example of anaerobic respiration.
• Anaerobes can maximize ATP production by dumping H⁺ and electrons on something like nitrate. Dojt 2004 demonstrated that PEMF can muck up this dumping.

What is reduction in terms of electrodes?

Part of this image of an electrode contains a bit of a scanning electron microscope photo of bacteria on the electrode. The electrodes were also covered with some sort of gauze. We are about to examine the concept of scanning voltammetry in which electrical potential differences, voltages, are cycled from very high to very low forcing currents to go in the natural and the opposite direction. Changes in the resistances based on Ohm’s Law, V=IR, can tell us something about the system. And how it might change in response to PEMF. V is the vola

Scanning Voltammetry to fingerprint reduction/oxidation reactions

The elaborate electrode system can viewed in an American Chemical Society site. was designed such that the electrode coated with the bacterium could detect This last phase of enzymatic activity using scanning volttammetry.

Microsoft PowerPoint was used to trace around a scan with just DQ. For the sake of this post, the meaning of each nuance of the SV “ducks” is not important, but that the authors were about to detect changes in the shape before and after PEMF is very exciting evidence that PEMF can affect electron transport systems.

After exposure of bacteria modified electrodes (glassy carbon, pencil graphite, and pyrolytic graphite) to 10 mT 50 Hz magnetic for 24 minutes a decrease of peak current of about 20% was observed for all three electrodes.

Fojt 2007 also looked at bacteria killing after PEMF as measured by “colony forming units.” Killing at different time points and magnetic fields from 2 to 10 mT were examined a well. E coli seemed to be more susceptible to killing. Statistics were not given. The authors did not attribute killing to changes in electron flow through the system in this publication.

E coli nitrate reductase, pulsed magnetic fields Jepson 2007

The Escherichia coli NapA (periplasmic nitrate reductase) contains a [4Fe-4S] cluster and a Mo-bis-molybdopterin guanine dinucleotide cofactor. The NapA holoenzyme associates with a di-heme c-type cytochrome redox partner (NapB). …..Spectropotentiometric Characterization of E. coli NapB Hemes—The UV-visible spectrum of oxidized NapB has a Soret band centered at 408 nm, a visible region peak at 531 nm, and a shoulder at 560 nm. The spectrum is typical of low spin ferric heme. Upon reduction, the Soret band maximum shifts to 420 nm, and peaks at 525 and 552 nm appear that are characteristic of low spin ferrous c-type cytochromessphaeroides NapA (midpoint potential Mo^6+/5+ > +350 mV), and the form of the Mo⁵⁺ EPR signal is quite distinct….”

These are some tiny tibits from a very biophysical paper. According to Wikipedia authors Electron Paramagnetic Resonance (EPR)uses frequencies of 9-10 kHz, pretty far from the 50 Hz used by Fojt 2007. Jepson 2007 saw signals in the 0.34 T region using this scanning process.

for the biohacker

Can the biohacker combine green light and PEMF for skin infections? My advice is to use it only to complement, not replace, standard of care provided by someone licensed o practice medicine. Let your healthcare provider what you are doing to supplement their care. There a many 7 color LED skin care devices from Amazon, Walmart, and Ebay. This particular seller is asking $29. I’m a bit dubious simply because other LED light wellness go to much more care to specify the lumens as well as the absence of dirty electricity. Red Light Therapy Home devices come with specified wavelengths, radiance in units of mW per cm².

I highly recommend Micro-Pulse.com PEMF devices simply because of affordability, an active forum of fellow hackers, and because the founder understands the physics of PEMF

 -Yellow Light
With wave length of 583 nm, this light mode can penetrate skin depth up to 1-2mm. Effective in reducing skin red spots, relieving skin swelling and pigment swelling.
 -Green Light
With wave length of 532nm, the light can penetrate skin depth up to 0.5-2mm , effective in calming senstitive skin. Recall the absorbance at 530 nm of Figure 1, Giordani & Buc

References

• Azeemi ST, Shaukat SF, Azeemi KS, Khan I, (2016) Mahmood K, Naz F. EFFECT OF VISIBLE RANGE ELECTROMAGNETIC RADIATIONS ON ESCHERICHIA COLI. Afr J Tradit Complement Altern Med. 2016 Nov 23;14(1):24-31. PMC free paper
• Fojt L, Strasák L, Vetterl V. (2007) Effect of electromagnetic fields on the denitrification activity of Paracoccus denitrificans. Bioelectrochemistry. 2007 Jan;70(1):91-5. Sci-Hub free paper.
• Giordani R, Buc J. (2004) Evidence for two different electron transfer pathways in the same enzyme, nitrate reductase A from Escherichia coli. Eur J Biochem. 2004 Jun;271(12):2400-7. . free paper
• Jepson BJ, Mohan S, Clarke TA, Gates AJ, Cole JA, Butler CS, Butt JN, Hemmings AM, Richardson DJ. (2007) Spectropotentiometric and structural analysis of the periplasmic nitrate reductase from Escherichia coli. J Biol Chem. 2007 Mar 2;282(9):6425-37. free paper
• Tunney JM, J. McMaster J, Garner CD,8.18 – Molybdenum and Tungsten Enzymes, Editor(s): Jon A. McCleverty, Meyer T (2003) J, Comprehensive Coordination Chemistry II, Pergamon, 2003, Pages 459-477, ISBN 9780080437484, Link