Vitronectin and its fragments purified as serum inhibitors of Staphylococcus aureus gamma-hemolysin and leukocidin, and their specific binding to the hlg2 and the LukS components of the toxins.

Staphylococcal gamma-hemolysin and leukocidin are bi-component cytolysins, consisting of LukF (or Hlg1)/Hlg2 and LukF/LukS, respectively. Here, we purified serum inhibitors of gamma-hemolysin and leukocidin from human plasma. Protein sequencing showed that the purified inhibitors of 62, 57, 50 and 38 kDa were the vitronectin fragments with truncation(s) of the C-terminal or both N- and C-terminal regions. The purified vitronectin fragments specifically bound to the Hlg2 component of gamma-hemolysin and the LukS component of leukocidin to form high-molecular-weight complexes with them, leading to inhibition of the toxin-induced lysis of human erythrocytes and human polymorphonuclear leukocytes, respectively. Intact vitronectin also showed inhibitory activity to the toxins. The ability of gamma-hemolysin and leukocidin to bind vitronectin and its fragments is a novel function of the pore-forming cytolysins.     

High-performance anion-exchange chromatography of ultraviolet-absorbing constituents of human urine

A 100-μl urine sample was chromatographed on a column packed with a strongly basic macroreticular anion-exchange resin (Diaion CDR-10, 5– μm diameter with a nominal 35% cross linkage). The elution was performed with a linear acetate gradient from 0 to 6.0 M at an average flow-rate of 0.72 ml/min and at an average pressure of 104 kg/cm². The relative standard deviation of retention times and peak height was ± 4% or less. The properties of the macroreticular anion-exchange resin, the effect of the particle size, the pH of acetate buffers, and the effect of the flow-rate of the eluent on the separation were investigated. Thirty three components of urine were then resolved and named.     

Assignment of a human serum glycoprotein SP-40,40 gene (CLI) to chromosome 8.

SP-40,40 is a serum glycoprotein consisting of two different subunits (alpha and beta) assembled into a dimer by disulfide bonds. Northern blot hybridization, using total RNA from several cell lines, showed that SP-40,40 is expressed in glioblastoma and testicular tumor cells, as well as hepatoma cells. Spot blot hybridization of flow-sorted human chromosomes, using a SP-40,40 cDNA fragment as a probe, localized the gene for SP-40,40 to human chromosome 8. This gene has been given the designation CLI, for complement lysis inhibitor, by the Human Gene Nomenclature Committee.     

Analysis of Slow Hyperpolarizing Potentials in Frog Taste Cells Induced by Glossopharyngeal Nerve Stimulation

Chemical Senses, 29,     

Measurement of Serine Acetyltransferase Activity in Crude Plant Extracts by a Coupled Assay System Using Cysteine Synthase

Serine acetyltransferase (SATase) (EC 2.3.1.30 [EC] ) catalyzes theformation of Oacetyl-L-serine (OAS) from L-serine in the presenceof acetyl-CoA. A novel assay method was developed for measuringthis enzyme activity in extracts from plant tissues. The assayconsists of a coupled system in which the OAS formed is convertedto cysteine by the addition of cysteine synthase (CSase) (EC4.2.99.8 [EC] ). Cysteine thus formed is determined colorimetricallyand serves as a measure for SATase activity. This method israpid, simple and sensitive, and can be readily adapted formeasurement of SATase activity in crude tissue extracts or homogenates. (Received January 14, 1987; Accepted April 27, 1987)     

Modification in Cell Shape Unrelated to Cellulose Microfibril Orientation in Growing Thallus Cells of Chaetomorpha moniligera

Cellulose microfibril orientation patterns in thallus cellsof Chaetomorpha moniligera were studied, and the relationshipbetween the microfibril and the peripheral microtubule arrangementsduring cell-shape modification by colchicine was examined. Inthe cuttings from growing thalli, linearly arranged cylindricalcells developed into cask-shaped cells during 4–6 daysof culture at 27?C. In the cylindrical cells, microfibrils formingthe innermost portion of the wall were arranged alternatelyin longitudinal and transverse directions, but peripheral microtubuleswere always arranged only in a longitudinal direction. Thesefeatures were also noted in the cask-shaped cells. Colchicineat 10^–3M and 3?10^–3M accelerated both cell expansionand wall thickening with matrix deposition, but the directionsin which both microfibrils and microtubules were arranged werethe same as those of the cylindrical cells. These results indicatethat (1) the microfibril and microtubule arrangements of Chaetomorphaare not necessarily correlated, (2) changes in cell shape ofChaetomorpha are not necessarily accompanied by changes in thearrangement of cell-wall microfibrils, and (3) colchicine playsa role in the loosening and thickening of cell walls by enhancingmatrix deposition. (Received June 2, 1986; Accepted February 13, 1987)     

Evolutionary relationships between laboratory mice and subspecies of Mus musculus based on the genetic study of pancreatic proteinase loci,Prt-1, Prt-2, Prt-3, and Prt-6

Various patterns of mouse pancreatic proteinase activity bands were observed on agarose gel electrophoresis. Prt-1 ^a and Prt-1 ^b genes control the positive (PRT-1A) and negative (PRT-1B) expression of tryptic band V, respectively; Prt-2 ^a and Prt-2 ^b correspond to chymotryptic bands II (PRT-2A) and III (PRT-2B); Prt-3 ^a and Prt-3 ^b control the low (PRT-3A) and high (PRT-3B) tryptic activities of band IV; the Prt-1 and Prt-3 loci are closely linked on the same chromosome; Prt-6 ^a and Prt-6 ^b correspond to tryptic bands I (PRT-6A) and I (PRT-6B). Twenty-four laboratory strains from the United States showed the phenotype PRT-1A, PRT-3A, and PRT-2A. Of laboratory strains established in Europe, 6 showed PRT-1A, PRT-3A, and PRT-2A, and 10 had PRT-1B, PRT-3A, and PRT-2A bands. Most wild mice around the world and their descendants showed the phenotype PRT-1B, PRT-3B, and PRT-2A. Only the phenotype of M. m. brevirostris was PRT-1A, PRT-3A, and PRT-2A, which was the same as most laboratory inbred strains. PRT-2B was observed mainly in Japanese (M. m. molossinus) and Korean (M. m. yamashinai) wild mice. PRT-6B was detected only in Mus spicilegus and Mus caroli, but all other mice including wild populations and laboratory strains showed PRT-6A. New biochemical phenotypes such as PRT-2C and PRT-3C were also found in this study.