Sulfated oviductal glycoproteins in the rabbit: quantitation by competitive enzyme-linked immunosorbent assay

The rabbit oviductal epithelium synthesizes and secretes a family of antigenically related, sulfated oviductal glycoproteins (SOG). Anti-SOG monoclonal antibodies (Mabs) were produced and two (Mab 1 and Mab 2) were selected for further characterization. Periodate oxidation of Western blots of oviductal fluid did not affect the binding of Mab 1 or Mab 2, thus suggesting that these antibodies recognized protein rather than carbohydrate epitopes on SOG. The specificity of Mab 1 was determined by Western blot analysis of tissues obtained from estrous rabbits and from the male rabbit reproductive tract. SOG was identified in tissue extracts of both the oviductal ampulla and isthmus. Cervix was the only non-oviductal tissue with which Mab 1 cross-reacted. Mab 1 was used to isolated SOG from whole oviductal fluid by immuno-affinity chromatography. Affinity-purified SOG and Mab 1 were used to develop a quantitative, SOG-specific, competitive enzyme-linked immunosorbent assay. This assay was used to quantify SOG in rabbit oviductal fluid collected during estrus and pseudopregnancy. SOG secretion during pseudopregnancy was resolved into two transient episodes of increased secretion. Maximum SOG secretion (X = 1039 +/- 199 micrograms/day) occurred within 48 h of the induction of pseudopregnancy. A second period of enhanced SOG secretion (X = 308 +/- 46 micrograms/day) occurred during the fifth and sixth days of pseudopregnancy. Baseline SOG secretion occurred during estrus at approximately 60% of maximum postovulatory secretion.     

Immunodetectable galactosyltransferase is associated only with human spermatozoa of high buoyant density

Human ejaculated spermatozoa are heterogeneous and can be separated into two distinct populations according to their respective buoyant densities. In order to investigate the functional differences between these two types of spermatozoa, we have searched for the presence of galactosyltransferase. A Western blot of sperm proteins following their electrophoresis was probed with an anti-galactosyltransferase serum revealing that this enzyme is present in human spermatozoa. Furthermore, galactosyltransferase is detectable only in those proteins isolated from the head of high density spermatozoa. These results suggest that ejaculated spermatozoa consist of two populations that are functionally different.     

Tetracycline production byStreptomyces aureofaciens: the time lag of production

Summary The exact time course of phosphate consumption in a tetracycline production byStreptomyces aureofaciens has been determined. The data have been compared with model simulations according to a model proposed by Votruba et al. (1984). This led to a revision of his equation for the rate of phosphate consumption and to the proposal that phosphate is consumed proportionally to the growth rate. In contradiction to the model simulations it was found that the length of the time lag of the production is independent of the initial phosphate concentration. While the model explains the time lag through inhibition of the production by phosphate, the measured data show that there must be another or an additional reason for the lag. Simultaneously with the start of the production the organism changes from an organic substrate to ammonia as nitrogen source.All experiments have been carried out in a bubble column of 651 working volume as fed batch fermentation. An autoanalyzer and a HPLC was coupled to the reactor for automatic measurement of phosphate, ammonia, sucrose and products in short intervals. Composition of the outlet gas, pH, pO₂, temperature and weight of the substrate flasks were monitored on-line.     

Evolutionary Divergence in the Structure of Myelin Basic Protein: Comparison of Chondrichthye Basic Proteins with Those from Higher Vertebrates

Abstract: A basic protein has been purified from the CNS myelin of the gummy shark (Mustelus antarticus). Electroblotting was used to examine the capacity of rabbit antisera raised against this electrophoretically pure protein to recognize myelin basic protein from higher vertebrates. The antisera bound to two shark proteins including the original polypeptide antigen and to chicken, bovine, and human myelin basic proteins. Thus, the shark protein appeared to possess antigenic determinants that have been retained through evolutionary divergence of these proteins. Whereas bovine basic protein caused experimental allergic encephalomyelitis in guinea pigs, animals that received injections of the shark protein showed neither clinical nor histological signs of this disease. However, tests for delayed-type hypersensitivity and for Arthus reaction following injection with the shark protein revealed a T-cell-mediated response to this antigen and substantial cross-reactivity with higher vertebrate basic proteins. Analysis of the amino acid composition of the shark protein, and comparison of its tryptic peptide map with that of the bovine protein, revealed substantial changes in the amino acid sequence. Although the shark protein has some antigenic determinants in common with the proteins from higher vertebrates, it appears that much of the structure differs.     

Characteristics of the relative maximum in the decay of delayed light emission from Pothos leaf following far-red excitation

Following illumination with wavelengths longer than 700 nm, the intensity of light emission from Pothos aurea leaf falls for 1 min and then increases to a maximum after 2 min in the dark. The spectrum of this minute-range liminescence matches that of prompt fluorescence excited at the same wavelength, but differs from that of prompt or minute-range delayed emission excited by wavelengths shorter than 700 nm. This emission is less sensitive to heat damage than millisecond delayed emission, and may originate from photosystem I.