Proteomic study of the brackish water mussel .

Background: We encountered the opportunity to study proteochemically a brackish water invertebrate animal, , belonging to the bivalves which stem from the second half of the Cambrian Period (about 510 million years ago). This way, we were able to compare it with the vertebrate animal, the frilled shark () that stems from a much later period of geologic time (Permian: 245-286 MYA).

Results: The mussel contains a well-adapted system of protein synthesis on the ER, protein folding on the ER, protein trafficking via COPI or clathrin-coated vesicles from endoplasmic reticulum (ER) to Golgi and plasmalemma, an equally well-developed system of actin filaments that with myosin forms the transport system for vesicular proteins and tubulin, which is also involved in ATP-driven vesicular protein transport via microtubules or transport of chromosomes in mitosis and meiosis.

Monoclonal antibody to phosphatidylserine inhibits Na+/K(+)-ATPase activity.

A monoclonal IgG, directed to phosphatidylserine (PS1G3), partially (40-50%) inhibited Na+/K(+)-ATPase activity (forward running reaction cycle) without affecting the K0.5 values for Na+,K+ and MgATP. The Hill or interaction coefficients (nH) for Na+ and K+ for this reaction were reduced from 3.

Quantitative analysis of residual detergent in proteoliposomes by Fourier transform infrared spectroscopy.

An infrared spectroscopic method has been developed to quantify the residual amount of detergent present in membranes, e.g., after reconstitution of a membrane protein in phospholipids.

Cation fluxes and Na+-K+-activated ATPase activity in erythrocytes of patients with essential hypertension.

Recently it has been claimed that the active potassium influx in erythrocytes of patients with essential hypertension would be increased. In view of the diagnostic and possibly therapeutic potential of this claim, we have determined the Na+-K+ activated ATPase activity and the affinity of the enzyme for Na+, K+, and ATP in membranes isolated from erythrocytes of hypertensive (with and without medication) and normotensive subjects. Subsequently, the active (ouabain-sensitive) sodium and potassium fluxes and their ratios have been determined after treatment of intact erythrocytes either with cold or with p-chloromercuribenzene-sulfonate (PCMBS).