ABSTRACT
An effective potential for longitudinal interactions between adjacent protofilaments in a microtubule is introduced. Our proposed interaction potential is a periodic and continuous function of the offset between two protofilaments, which also incorporates the bending energy of protofilaments. This potential produces the results of atomistic simulations. Further, using the potential, a Monte Carlo simulation gives results for the skew angles of observed structures that are in good agreement with experiments.
Subject(s)
Biophysics/methods , Microtubules/chemistry , Animals , Computer Simulation , Cryoelectron Microscopy , Dimerization , Fourier Analysis , Humans , Models, Biological , Models, Molecular , Models, Statistical , Monte Carlo Method , Organelles/chemistry , Protein Conformation , Stochastic ProcessesABSTRACT
We show that the hydrophobicity of sequences is the leading term in Miyazawa-Jernigan interactions. Being the source of additive (solvation) terms in pair-contact interactions, they were used to reduce the energy parameters while resulting in a clear vector manipulation of energy. The reduced (additive) potential performs considerably successful in predicting the statistical properties of arbitrary structures. The evaluated designabilities of the structures by both models are highly correlated. Suggesting geometrically nondegenerate vectors (structures) as proteinlike structures, the additive model is a powerful tool for protein design. Moreover, a crossing point in the log-linear diagram of designability ranking shows that about 1/e of the structures have designabilities above the average, independent on the used model.
Subject(s)
Amino Acids/chemistry , Models, Chemical , Models, Molecular , Proteins/chemistry , Solvents/chemistry , Binding Sites , Computer Simulation , Models, Statistical , Protein Binding , Protein ConformationSubject(s)
Acrodermatitis/drug therapy , Zinc/therapeutic use , Adult , Female , Follow-Up Studies , Humans , Infant , Long-Term Care/methods , Zinc/deficiencyABSTRACT
Sexually transmitted infections (STIs) in young people are increasing, with children aged less than 16 years being particularly vulnerable. We compared the demographic details, spectrum of infection, contraceptive practice and source of referral in patients aged less than 16 years attending 2 genitourinary clinics, one in Swansea and the other in London. In the London population, children aged less than 16 years represented 0.7% of the total new attendances compared with 1.4% in Swansea. The female to male ratio was almost 4:1 in both clinics with most infections confined to female attenders. In females the incidence of chlamydial infection, genital warts and anaerobic (bacterial) vaginosis was 5.5%, 19% and 8%, respectively in London compared with 27%, 32% and 36% in Swansea. Seventy-two per cent of patients attending the clinic in London were self referred compared with 40% in Swansea. Contraceptive practice was also markedly different in the 2 populations, and over one-third of children in both clinics used no contraception. The high incidence of STIs in both populations and low use of contraception has serious implications for the sexual health of young people and emphasizes the need for effective sexual health education at an early age.
