Exploring and improving life

Women give life, women engineer life…

Nettie Maria Stevens (1861 – 1912)

Nettie Stevens.
Source: Wikimedia Commons

In 1906, Nettie Maria Stevens discovered that sex is determined by chromosoms.

Alice Augusta Ball (1892 – 1916)

Alice Augusta Ball designed a process to make chaulmoogra oil injectable and absorbable by the body, in order to painlessly cure leprosis.

The credit for her invention was taken by college president Arthur L. Dean, until her former colleague restablished the truth by naming the process after her.

The injections became the most reliable way to help keep the disease under control until new drugs came available in the 1940s.

Rosalind Elsie Franklin (1920-1958)

Rosalind Elsie Franklin was working on DNA structure at King’s College of London with Raymond Gosling and Maurice Wilkins. She presented her data at a lecture in November 1951, in King’s College of London, at which James Watson was in attendance and had not yet built his DNA model. In her lecture notes, Franklin wrote the following:

The results suggest a helical structure (which must be very closely packed), containing 2, 3, or 4 co-axial nucleic acid chains per helical unit, and having the phosphate groups near the outside.
Lecture notes of Rosalind Franklin, November 1951

Maurice Wilkins, who hated Rosalind Franklin, proclamed later in his self-written biography that he was the first to propose an helical structure.

In 1952, Rosalind Franklin took an X-ray diffractions photograph of DNA called “Photograph 51”, which demonstrates, using mathematical formula, its helical structure.

DNA diffraction pattern — Photograph 51: DNA X-ray diffraction image.
Source: King’s college of London

X-ray diffraction process.
Source: X-ray crystallography of biological macromolecules

In March 1953, Rosalind Elsie Franklin and Raymond Gosling wrote a draft of their conclusions on the helical structure, available on The Rosalind Franklin Papers: A Note on Molecular Configuration in Sodium Thymonucleate (PDF)

Sources:
Rosalind Franklin and the double helix by Lynne Osman Elkin
How Rosalind Franklin Discovered the Helical Structure of DNA: Experiments in Diffraction, by Gregory Braun, Dennis Tierney, and Heidrun Schmitzer (PDF), with reference to the book of Anne Sayre: “Rosalind Franklin and DNA”
Biography of Rosalind Franklin on “DNA from the beginning”
The double helix and the wronged heroine, by Brenda Maddox (PDF)

Francis Crick, James Watson and Maurice Wilkins continued Rosalind Franklin’s research, and got a Nobel prize in 1962.

In 1954, Rosalind Franklin discovered the virus structure. Her research was completed by Aaron Klug who got the Nobel prize in 1982.

TMV virus under magnification.
Source: Wikimedia Commons

X ray diffraction pattern of TMV — Franklin’s X-ray diffraction pattern of TMV.
Source: ResearchGate

The process of studying patterns of diffraction to determine biological macromolecules structure (such as DNA or proteins) has been improved later using crystals of the macromolecules (“crystallography”).

Dorothy Hodgkin (1910 – 1994)

Dorothy Hodgkin improved protein crystallography and was awarded a Nobel Prize in Chemistry in 1964 for her determinations of the structures of important biochemical substances: steroid, penicillin, B12 vitamin and insulin.

X-ray crystallography is a scientific method of determining the precise arrangements of elements in a crystal : the beams of X-ray strikes a crystal and causes the beam of light to diffract into many specific directions. The crystal of proteins is obtained by purifying a solution of proteins and adding different agents to improve their saturation.
Using X-ray crystallography, chemists are able to determine the internal structures and bonding arrangements of minerals and molecules, including the structures of large complex molecules, such as proteins and DNA.

More about crystallography:
Protein Crystallization: Basic Approach
Guide to Understanding X-ray Crystallography (PDF)

Esther Lederberg (1922 – 2006)

Esther Lederberg in her lab.
Source: Wikimedia Commons

Esther Lederberg made important discoveries in bacterial genetics with her husband Joshua Lederberg. He didn’t share the Nobel prize with her in 1958.

She helped discover and understand the genetic mechanisms of specialized transduction. These contributions laid the foundation for much of the genetics work done in the latter half of the twentieth century.

Rachel Carson (1907 – 1964)

Rachel Carson investigated and revealed to the public, in her book “Silent Spring”, 1962, the negative effects of pesticides on the environment. She raised a consciousness about the environment, which led to the prohibition of the use of DDT, a dangerous insecticide.

Lynn Margulis (1938 – 2011)

Lynn Margulis and James Lovelock resurrected a long-ignored idea that the organelles within eukaryotes were once free-living bacteria that had once invaded other bacterial forms and became symbiotic.

Learn more about Lynn Margulis and James Lovelock

Lynn Margulis’s expertise in microbes led her, in the mid-Seventies, to the British atmospheric chemist James Lovelock, who had come to suspect that living organisms had a greater effect on the atmosphere than was commonly recognised. Together they proposed a theory that Earth itself — its atmosphere, the geology and the organisms that inhabit it — is a self-regulating system in which living organisms help to regulate the terrestrial and atmospheric conditions that make the planet habitable.

In particular they suggested that plankton act as a living thermostat, helping to regulate global temperature; that bogs and peat lands affect glaciers as the organisms within them release and absorb greenhouse gases; and that colonies of bacteria and other microbes in tidal mud flats process enough salt to help keep ocean salinity fairly constant. Lovelock suggested that they call their hypothesis Gaia, after the ancient Greek goddess of the Earth.

Gertrude B. Elion (1918 – 1999)

Gertrude B. Elion and George H. Hitchings developed a method of research using biochemical difference between normal human cells and pathogen cells. They were awarded the Nobel Prize in Medicine in 1988.
With this method, they were able to create new drugs that were effective against leukemia, autoimmune disorders, urinary-tract infections, gout, malaria, and viral herpes

Learn more about Gertrude B. Elion and George H. Hitchings

In 1944 Elion joined the Burroughs Wellcome Laboratories (later part of Glaxo Wellcome; today known as GlaxoSmithKline). There she was first the assistant and then the colleague of Hitchings, with whom she worked for the next four decades. Elion and Hitchings developed an array of new drugs that were effective against leukemia, autoimmune disorders, urinary-tract infections, gout, malaria, and viral herpes. Their success was due primarily to their innovative research methods, which marked a radical departure from the trial-and-error approach taken by previous pharmacologists. Elion and Hitchings pointedly examined the difference between the biochemistry of normal human cells and those of cancer cells, bacteria, viruses, and other pathogens (disease-causing agents). They then used this information to formulate drugs that could kill or inhibit the reproduction of a particular pathogen, leaving the human host’s normal cells undamaged.

Françoise Barré Sinoussi (1947 – …)

F Barre-Sinoussi — Françoise Barre-Sinoussi.
Source: An Interview with Françoise Barré-Sinoussi on amfAR

Françoise Barré Sinoussi and Luc Montagnier discovered the HIV virus. They won a Nobel prize in medicine in 2008.

Tu Youyou (1930 – …)

Tu Youyou developed a cure for Malaria and won a Nobel prize in medicine in 2015.

Emmanuelle Charpentier (1968 – …)
& Jennifer Doudna (1964 – …)

Emmanuelle Charpentier & Jennifer Doudna.
Source: Charpentier and Doudna win Princess of Asturias Award for gene-editing technology on Euronews

Emmanuelle Charpentier and Jennifer Doudna developed a process called “CRISP-R Cas9” released in 2012, which can activates or inhibits the expression of a gene.
CRISPR is short for “clustered regularly interspaced short palindromic repeats.” The term makes reference to a series of repetitive patterns in the DNA. Cas9 is a protein that can recognize the sequence stored within CRISPR patterns and cut all DNA with a matching sequence.

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