Three-dimensional protein structures usually contain regions of local order, called secondary structure, such as α-helices and β-sheets. Secondary structure is characterized by the local rotational state of the protein backbone, quantified by two dihedral angles called ϕ and ψ. Particular types of secondary structure can generally be described by a single (diffuse) location on a two-dimensional...

The pioneering work of Ramachandran and colleagues emphasized the dominance of steric constraints in specifying the structure of polypeptides. The ubiquitous Ramachandran plot of backbone dihedral angles (ϕ and ψ) defined the allowed regions of conformational space. These predictions were subsequently confirmed in proteins of known structure. Ramachandran and colleagues also investigated the in...

I n the article by Maas et al, “Plasma Nitrate and Incidence of Cardiovascular Disease and All-Cause Mortality in the Community: The Framingham Offspring Study,” which published online on November 18, 2017, and appeared in the November 2017 issue of the journal (J Am Heart Assoc. 2017;6:e006224. DOI: 10.1161/JAHA.117.006224), on page 1, the seventh author’s name was incorrectly written as Ramac...

A striking demonstration that sound-object correspondences are not completely arbitrary is that adults map nonsense words with rounded vowels (e.g. bouba) to rounded shapes and nonsense words with unrounded vowels (e.g. kiki) to angular shapes (Köhler, 1947; Ramachandran & Hubbard, 2001). Here we tested the bouba/kiki phenomenon in 2.5-year-old children and a control group of adults (n =20 per ...

The recently determined C. elegans P-glycoprotein (Pgp) structure revealed significant deviations compared to the original mouse Pgp structure, which suggested possible misinterpretations in the latter model. To address this concern, we generated an experimental electron density map from single-wavelength anomalous dispersion phasing of an original mouse Pgp dataset to 3.8 Å resolution. The map...

We show that each of Thompson’s groups F , T , and V has infinitely many ends relative to the groups F[0,1/2], T[0,1/2], and V[0,1/2) (respectively). As an application, we simplify the proof, due to Napier and Ramachandran, that F , T , and V are not Kähler groups. We go on to show that Thompson’s groups T and V have Serre’s property FA. The main theorems together answer a question on Bestvina’...

The line shapes detected in coherent femtosecond vibrational spectroscopies contain direct signatures of peptide conformational fluctuations through their effect on vibrational frequencies and intermode couplings. These effects are simulated in trialanine using a Green's function solution of a stochastic Liouville equation constructed for four collective bath coordinates (two Ramachandran angle...