The galactose--glucose binding protein possesses two structural domains bordering a ligand binding cleft, with three polypeptide strands serving as a flexible hinge connecting the two domains. The hinge is known to bend, enabling the cleft to open by an angle of at least 18 degrees. Here the twisting motions of the hinge were examined by placing pairs of engineered cysteines on the perimeter of the cleft to generate six stable di-cysteine proteins. Each cysteine pair introduced reactive sulfhydryls into both rims of the cleft, one in the N-terminal domain and the other in the C-terminal domain. Collisions between sulfhydryls in different domains were trapped by disulfide formation, yielding sensitive detection of large amplitude domain rotations. When the cleft was occupied by the ligand D-glucose, counterclockwise hinge twist rotations were detected with amplitudes up to 36 degrees, and frequencies ranging from 10(1) to 10(3) collisions s-1. Removal of ligand from the cleft increased the range of twist angles 3-fold and the frequency of motions up to 10(2)-fold. Thus, in this representative hinged cleft protein, large amplitude hinge twist motions occur on biologically relevant timescales. The functional implications of such motions are discussed.

Background Obesity related hospital admissions increased 700% in last decade. Assessment of availability of suitable bariatric equipment across clinical areas is essential to optimise care environment for this vulnerable group to appropriate levels of ‘Safety &Quality’. Aim To assess availability of suitable equipment through gap analysis against CMACE/RCOG recommendations, before move of reconfigured maternity services (merger of two hospitals) to new unit. Method Evaluation of above in all settings(primary and secondary care clinics, scan suites, in-patient &day assessment wards, delivery suite and theatres) through a structured proforma. Results Pre move assessment identified gaps in availability of some bariatric equipment in all key areas. Safe weight threshold of examination couches &theatre tables were below recommended>250kg. Since move to new centre this availability was ensured in all clinics, wards &theatres as gap analysis &action implemented resulted in procurement of suitable equipment for all settings. Currently stand on scales and BP cuffs of varying sizes are available but Sit on scales, extra wide (EW) wheel chairs &toilet seats/commodes were lacking. It was noted that BMI charts/wheels had maximum limit of only 186kg/BMI 65. Conclusions/Recommendations CMACE/RCOG guidance has provided an opportunity for maternity services to take a lead role to ensure that bariatric policies for obese pregnant women are included in generic trust bariatric policies. Work is in progress to add a chapter on this within our trust bariatric policy. Disparity in equipment models noted in this review is currently being addressed through a phased electively planned procurement programme.