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[[[alpha-.sup.15]N]Lysine-labeled rhodopsin, prepared by expression of a synthetic gene in HEK293 cells, was investigated both by conventional and transverse relaxation optimized spectroscopy-type heteronuclear single quantum correlation spectroscopy. Whereas rhodopsin contains 11 lysines, 8 in cytoplasmic loops and 1 each in the C-terminal peptide sequence and the intradiscal and transmembrane domains, only a single sharp peak was observed in dodecyl maltoside micelles. This result did not change when dodecyl maltoside was replaced by octyl glucoside or octyl glucoside-phospholipid-mixed micelles. Additional signals of much lower and variable intensity appeared at temperatures above 20 [degrees] C and under denaturing conditions. Application of the transverse relaxation optimized spectroscopy sequence resulted in sharpening of resonances but also losses of signal intensity. The single peak observed has been assigned to the C-terminal Lys-339 from the following lines of evidence. First, the signal is observed in HNCO spectra of rhodopsin, containing the labeled [[sup.13]C]Ser-338/[[sup.15]N]Lys-339 dipeptide. Second, addition of a monoclonal anti-rhodopsin antibody that binds to the C-terminal 8 aa of rhodopsin caused disappearance of the peak. Third, truncated rhodopsin lacking the C-terminal sequence Asp-330-Ala-348 showed no signal, whereas the enzymatically produced peptide fragment containing the above sequence showed the single peak. The results indicate motion in the backbone amide groups of rhodopsin at time scales depending on their location in the sequence. At the C terminus, conformational averaging occurs at the nanosecond time scale but varies from microsecond to millisecond in other parts of the primary sequence. The motions reflecting conformational exchange may be general for membrane proteins containing transmembrane helical bundles.

In orthopaedic technology unilateral leg amputees are provided with prosthesis which are attached through a shaft to the remaining part of the leg. The prosthesis legs are built according to manufacturer’s specifications and get adjusted to the individual needs through motion analysis. If the prosthesis is not adjusted correctly to the individual needs of the user, the chance for development of arthritis in the remaining knee joint is greatly increased. The goal of this paper is to develop a procedure based on AEA to detect signs of arthritis in the remaining knee joint early and the base of a procedure for a future assessment of the quality of the care. The measurement system consists of the AEA - measurement device, a force plate to measure ground reaction forces, two strain gauges which are attached to handles on a test rig and two video cameras which record the movement from frontal and sagittal view. The amputee performs a standard movement in the test rig which consists of three knee bends in ten seconds while wearing the prosthesis legs. The test rig is provided so the amputee can support themselves using arms and hands as prosthesis’ support during the extension phase of the knee bend. The posture and load of the knee joint during the movement is analyzed with the video and force data. The ground reaction forces show the load distribution between the remaining leg and the prosthesis and its support during the movement. The hand forces give clues how well the amputee can balance and which arm is favored under load. By combining kinematic data and AEA the state of the load transfer zones can be evaluated. Thus, it’s possible to examine the remaining knee joint for defects and evaluate the quality of the prosthesis adjustment.

The small 2J(C4',H5') heteronuclear coupling constant for uniformly 13C labeled 19-mer RNA hairpin indicates a gauche+ rotamer conformation about the backbone angle. In the oligonucleotides, the stereospecific assignment of the H5' diastereotopic protons depends on the signs of the 2J(C4',H5') coupling constants. For majority regions in the hairpin, the H5'(super (pro-R)) protons resonate downfield of the H5'(super (pro-S)) protons. A sensitive NMR method is proposed for estimating the homonuclear 3J(H4',H5') and heteronuclear 2J(C4',H5') coupling constants in the 13C labeled RNA.