Herman Russell Branson (August 14, 1914 – June 7, 1995) was an American physicist, chemist, best known for his research on the alpha helix protein structure, and was also the president of two colleges.
The United States of America (USA), commonly known as the United States or America, is a country composed of 50 states, a federal district, five major self-governing territories, and various possessions. At 3.8 million square miles, the United States is the world's third or fourth largest country by total area and is slightly smaller than the entire continent of Europe's 3.9 million square miles. With a population of over 327 million people, the U.S. is the third most populous country. The capital is Washington, D.C., and the largest city by population is New York City. Forty-eight states and the capital's federal district are contiguous in North America between Canada and Mexico. The State of Alaska is in the northwest corner of North America, bordered by Canada to the east and across the Bering Strait from Russia to the west. The State of Hawaii is an archipelago in the mid-Pacific Ocean. The U.S. territories are scattered about the Pacific Ocean and the Caribbean Sea, stretching across nine official time zones. The extremely diverse geography, climate, and wildlife of the United States make it one of the world's 17 megadiverse countries.
A physicist is a scientist who specializes in the field of physics, which encompasses the interactions of matter and energy at all length and time scales in the physical universe. Physicists generally are interested in the root or ultimate causes of phenomena, and usually frame their understanding in mathematical terms. Physicists work across a wide range of research fields, spanning all length scales: from sub-atomic and particle physics, through biological physics, to cosmological length scales encompassing the universe as a whole. The field generally includes two types of physicists: experimental physicists who specialize in the observation of physical phenomena and the analysis of experiments, and theoretical physicists who specialize in mathematical modeling of physical systems to rationalize, explain and predict natural phenomena. Physicists can apply their knowledge towards solving practical problems or to developing new technologies.
A chemist is a scientist trained in the study of chemistry. Chemists study the composition of matter and its properties. Chemists carefully describe the properties they study in terms of quantities, with detail on the level of molecules and their component atoms. Chemists carefully measure substance proportions, reaction rates, and other chemical properties. The word 'chemist' is also used to address Pharmacists in Commonwealth English.
Branson received his B.S. from Virginia State College in 1936, and his Ph.D. in physics from the University of Cincinnati, under the direction of Boris Padolsky, in 1939. His thesis was in three parts, the first involved the interaction of x-rays with Tubifex Tubifex, the second involving the design and construction of an x-ray intensity measuring device, and the third section on the quantization of mass using the Dirac Equation.After a stint at Dillard University, he joined Howard University in 1941 as an assistant professor of physics and chemistry. As a scientist, Branson made significant contributions to how proteins work, and how they contribute to diseases such as sickle cell anemia. He remained at Howard for 27 years, achieving increasingly important positions, eventually becoming head of the physics department, director of a program in experimental science and mathematics, and working on the Office of Naval Research and Atomic Energy Commission Projects in Physics at Howard University. One of his students would include Marie Maynard Daly who was the first woman of color in the United States to earn her doctorate in Chemistry.
The University of Cincinnati is a public research university in Cincinnati Ohio. Founded in 1819 as Cincinnati College, it is the oldest institution of higher education in Cincinnati and has an annual enrollment of over 44,000 students, making it the second largest university in Ohio. It is part of the University System of Ohio.
Dillard University is a private, historically black, liberal arts college in New Orleans, Louisiana, United States. Founded in 1930 and incorporating earlier institutions that were founded as early as 1869 after the American Civil War, it is affiliated with the United Church of Christ and the United Methodist Church.
Howard University is a private, federally chartered historically black university (HBCU) in Washington, D.C. It is categorized by the Carnegie Foundation as a research university with higher research activity and is accredited by the Middle States Commission on Higher Education.
In 1948, Branson took a leave and spent time at the California Institute of Technology, in the laboratory of the chemist Linus Pauling. There he was assigned work on the structure of proteins, specifically to use his mathematical abilities to determine possible helical structures that would fit both the available X-ray crystallography data and a set of chemical restrictions outlined by Pauling.After some months of work, Branson handed in a report narrowing the possible structures to two helices: a tighter coil Pauling termed "alpha," and a looser helix called "gamma." Branson then returned to Howard to work on other projects. Some months later he received a letter from Pauling along with a draft manuscript of a paper detailing the two helixes, with Branson listed as third author (after Pauling and his assistant Robert Corey, the laboratory's expert in transforming X-ray data into precise models). Pauling asked for suggestions. Branson replied in a letter that it was fine as written, approved submission to the Proceedings of the National Acaademy of Sciences, and asked for 25 preprints when published.
The California Institute of Technology (Caltech) is a private doctorate-granting research university in Pasadena, California. Known for its strength in natural science and engineering, Caltech is often ranked as one of the world's top-ten universities.
Linus Carl Pauling was an American chemist, biochemist, peace activist, author, educator, and husband of American human rights activist Ava Helen Pauling. He published more than 1,200 papers and books, of which about 850 dealt with scientific topics. New Scientist called him one of the 20 greatest scientists of all time, and as of 2000, he was rated the 16th most important scientist in history.
A helix, plural helixes or helices, is a type of smooth space curve, i.e. a curve in three-dimensional space. It has the property that the tangent line at any point makes a constant angle with a fixed line called the axis. Examples of helices are coil springs and the handrails of spiral staircases. A "filled-in" helix – for example, a "spiral" (helical) ramp – is called a helicoid. Helices are important in biology, as the DNA molecule is formed as two intertwined helices, and many proteins have helical substructures, known as alpha helices. The word helix comes from the Greek word ἕλιξ, "twisted, curved".
Branson went on to a significant career, eventually serving as president of Central State University in Wilberforce, Ohio, from 1968–1970, and then president of Lincoln University until his retirement in 1985. He was active in increasing federal funding for higher education, and helped found the National Association for Equal Opportunity in Higher Education in 1969.
Central State University (CSU) is a public, historically black university (HBCU) located in Wilberforce, Ohio, United States. It is a member-school of the Thurgood Marshall College Fund.
Lincoln University (LU) is public historically black university in Oxford, Pennsylvania. Founded as a private university in 1854, it has been a public institution since 1972 and was the United States' first degree-granting HBCU. Its main campus is located on 422 acres near the town of Oxford in southern Chester County, Pennsylvania. The university has a second location in University City, Philadelphia. Lincoln University provides undergraduate and graduate coursework to approximately 2,000 students. The University is a member-school of the Thurgood Marshall College Fund.
In 1984 Branson wrote Pauling biographers Victor and Mildred Goertzel implying that his contribution to the alpha helix had been greater than the final paper indicated. "I took my work to Pauling who told me that he thought they [the proposed alpha and gamma helixes] were too tight, that he thought that a protein molecule should have a much larger radius so that water molecules could fit down inside and cause the protein to swell," he wrote. "I went back and worked unsuccessfully to find such a structure." When he received Pauling's note with the draft manuscript, Branson wrote, "I interpreted this letter as establishing that the alpha and gamma in my paper were correct and that the subsequent work done was cleaning up or verifying. The differences were nil." He added in his letter to the Goertzels that he "resented" the later attention lavished on Pauling and Corey.The conservative watchdog group Accuracy in Media referred to the incident in an attack on Pauling in 1994. The available records, historical context, knowledge of the personalities involved, and studies of Pauling's laboratory and methods at the time have led most historians to accord greater credit to Pauling and Corey.
Accuracy In Media (AIM) is an American non-profit news media watchdog founded in 1969 by economist Reed Irvine. AIM describes itself as "a non-profit, grassroots citizens watchdog of the news media that critiques botched and bungled news stories and sets the record straight on important issues that have received slanted coverage." It has a politically conservative stance.
The alpha helix (α-helix) is a common motif in the secondary structure of proteins and is a right hand-helix conformation in which every backbone N−H group donates a hydrogen bond to the backbone C=O group of the amino acid located three or four residues earlier along the protein sequence.
Francis Harry Compton Crick was a British molecular biologist, biophysicist, and neuroscientist. In 1953, he co-authored with James Watson the academic paper proposing the double helix structure of the DNA molecule. Together with Watson and Maurice Wilkins, he was jointly awarded the 1962 Nobel Prize in Physiology or Medicine "for their discoveries concerning the molecular structure of nucleic acids and its significance for information transfer in living material". The results were based partly on fundamental studies done by Rosalind Franklin, Raymond Gosling and Wilkins.
Protein secondary structure is the three dimensional form of local segments of proteins. The two most common secondary structural elements are alpha helices and beta sheets, though beta turns and omega loops occur as well. Secondary structure elements typically spontaneously form as an intermediate before the protein folds into its three dimensional tertiary structure.
Maurice Hugh Frederick Wilkins was a New Zealand-born British physicist and molecular biologist, and Nobel laureate whose research contributed to the scientific understanding of phosphorescence, isotope separation, optical microscopy and X-ray diffraction, and to the development of radar. He is best known for his work at King's College London on the structure of DNA.
Sir William Lawrence Bragg, was an Australian-born British physicist and X-ray crystallographer, discoverer (1912) of Bragg's law of X-ray diffraction, which is basic for the determination of crystal structure. He was joint winner of the Nobel Prize in Physics in 1915: "For their services in the analysis of crystal structure by means of X-ray", an important step in the development of X-ray crystallography.
A coiled coil is a structural motif in proteins in which 2–7 alpha-helices are coiled together like the strands of a rope. Many coiled coil-type proteins are involved in important biological functions such as the regulation of gene expression, e.g. transcription factors. Notable examples are the oncoproteins c-Fos and c-jun, as well as the muscle protein tropomyosin.
Alpha Chi Sigma (ΑΧΣ) is a professional fraternity specializing in the fields of the chemical sciences. It has both collegiate and professional chapters throughout the United States consisting of both men and women and numbering more than 70,000 members. The fraternity aims to bring together students and professionals pursuing a wide variety of chemistry-related careers.
A Ramachandran plot, originally developed in 1963 by G. N. Ramachandran, C. Ramakrishnan, and V. Sasisekharan, is a way to visualize energetically allowed regions for backbone dihedral angles ψ against φ of amino acid residues in protein structure. The figure at left illustrates the definition of the φ and ψ backbone dihedral angles. The ω angle at the peptide bond is normally 180°, since the partial-double-bond character keeps the peptide planar. The figure at top right shows the allowed φ,ψ backbone conformational regions from the Ramachandran et al. 1963 and 1968 hard-sphere calculations: full radius in solid outline, reduced radius in dashed, and relaxed tau (N-Cα-C) angle in dotted lines. Because dihedral angle values are circular and 0° is the same as 360°, the edges of the Ramachandran plot "wrap" right-to-left and bottom-to-top. For instance, the small strip of allowed values along the lower-left edge of the plot are a continuation of the large, extended-chain region at upper left.
"Molecular Structure of Nucleic Acids: A Structure for Deoxyribose Nucleic Acid" was the first article published to describe the discovery of the double helix structure of DNA, using X-ray diffraction and the mathematics of a helix transform. It was published by Francis Crick and James D. Watson in the scientific journal Nature on pages 737–738 of its 171st volume.
William Thomas Astbury FRS was an English physicist and molecular biologist who made pioneering X-ray diffraction studies of biological molecules. His work on keratin provided the foundation for Linus Pauling's discovery of the alpha helix. He also studied the structure for DNA in 1937 and made the first step in the elucidation of its structure.
The history of molecular biology begins in the 1930s with the convergence of various, previously distinct biological and physical disciplines: biochemistry, genetics, microbiology, virology and physics. With the hope of understanding life at its most fundamental level, numerous physicists and chemists also took an interest in what would become molecular biology.
Maurice Loyal Huggins was a scientist who independently conceived the idea of hydrogen bonding and who was an early advocate for their role in stabilizing protein secondary structure. An important polymer theory, Flory–Huggins theory, is also named after him.
A pi helix is a type of secondary structure found in proteins. Although once thought to be rare, short π-helices are found in 15% of known protein structures and are believed to be an evolutionary adaptation derived by the insertion of a single amino acid into an α-helix. Because such insertions are highly destabilizing, the formation of π-helices would tend to be selected against unless it provided some functional advantage to the protein. π-helices therefore are typically found near functional sites of proteins.
A 310 helix is a type of secondary structure found in proteins and polypeptides. Of the numerous protein secondary structures present, the 310-helix is the fourth most common type observed; following α-helices, β-sheets and reverse turns. 310-helices constitute nearly 10–15% of all helices in protein secondary structures, and are typically observed as extensions of α-helices found at either their N- or C- termini. Because of the α-helices tendency to consistently fold and unfold, it has been proposed that the 310-helix serves as an intermediary conformation of sorts, and provides insight into the initiation of α-helix folding.
Robert Brainard Corey was an American biochemist, mostly known for his role in discovery of the α-helix and the β-sheet with Linus Pauling. Also working with Pauling was Herman Branson. Their discoveries were remarkably correct, with even the bond lengths being accurate until about 40 years later. The α-helix and β-sheet are two structures that are now known to form the backbones of many proteins.
Alpha sheet is an atypical secondary structure in proteins, first proposed by Linus Pauling and Robert Corey in 1951. The hydrogen bonding pattern in an alpha sheet is similar to that of a beta sheet, but the orientation of the carbonyl and amino groups in the peptide bond units is distinctive; in a single strand, all the carbonyl groups are oriented in the same direction on one side of the pleat, and all the amino groups are oriented in the same direction on the opposite side of the sheet. Thus the alpha sheet accumulates an inherent separation of electrostatic charge, with one edge of the sheet exposing negatively charged carbonyl groups and the opposite edge exposing positively charged amino groups. Unlike the alpha helix and beta sheet, the alpha sheet configuration does not require all component amino acid residues to lie within a single region of dihedral angles; instead, the alpha sheet contains residues of alternating dihedrals in the traditional right-handed (αR) and left-handed (αL) helical regions of Ramachandran space. Although the alpha sheet is only rarely observed in natural protein structures, it has been speculated to play a role in amyloid disease and it was found to be a stable form for amyloidogenic proteins in molecular dynamics simulations. Alpha sheets have also been observed in X-ray crystallography structures of designed peptides.
Harvey Akio Itano was an American biochemist best known for his work on the molecular basis of sickle cell anemia and other diseases. In collaboration with Linus Pauling, Itano used electrophoresis to demonstrate the difference between normal hemoglobin and sickle cell hemoglobin; their 1949 paper "Sickle Cell Anemia, a Molecular Disease" was a landmark in both molecular medicine and protein electrophoresis.
Barbara Wharton Low was a biochemist, biophysicist, and a researcher involved in discovering the structure of penicillin and the characteristics of other antibiotics. Her early work at Oxford University with Dorothy Hodgkin used X-ray crystallography to confirm the molecular structure of penicillin, which at the time was the largest molecule whose structure has been determined using that method. Later graduate work saw her study with Linus Pauling and Edwin Cohn before becoming a professor in her own right. Low's laboratory would accomplish the discovery of the pi helix, investigate the structure of insulin, and conduct research into neurotoxins.