High-performance liquid chromatography of peptides on a macroreticular cation-exchange resin: Application to peptide mapping of Bence-Jones proteins

A high-performance liquid chromatography system has been developed for analytical peptide mapping and preparative peptide separation. The method uses a macroreticular cation-exchange resin of the styrene-divinylbenzene type, having a relatively small particle size (6 ± 1 μm) and a high crosslinkage (35%). Elution was performed with a linear gradient of increasing salt and organic solvent concentration for monitoring the effluent at 210 nm. The system showed remarkable peak resolution and excellent mechanical and chemical stability, and high precision analysis of tryptic digests of S-aminoethyl Bence-Jones proteins was achleved in less than 120 min with nanomolar to micromolar quantities of the samples. The isolated peptides could be subjected to subsequent chemical determinations directly or after simple desslting process.     

A simple enzymatic differential assay for diamines, spermidine, and spermine in urine and blood

This rapid, reliable enzymatic differential assay method for diamines (putrescine plus cadaverine), spermidine, and spermine in urine and blood is suitable for practical routine use and does not require special and expensive equipment. The method is based on a combination of the substrate specificities of two amine oxidases, i.e., polyamine oxidase from A. terreus and putrescine oxidase from M. rubens. Quinone dye, derived from hydrogen peroxide generated in each of three end-point reactions, is measured spectrophotometrically at 555 nm, and the amounts of the respective amines are simply calculated. Analytical recoveries and precisions are acceptable. The proposed method produces results which correlate with high-performance liquid chromatography. Twenty or more assays can be done within 3 hr by one technician.     

Studies of the role of steroid hormone in the regulation of oocyte maturation in cattle

Background  

The objective of this study was to investigate whether the steroid hormone(s) secreted from cumulus-oocyte complexes (COCs) is a prerequisite for bovine oocyte maturation and cumulus expansion using aminoglutethimide (AGT), a P450 cholesterol side-chain cleavage inhibitor.     

Development of second generation merozoites of Leucocytozoon caulleryi in vitro

Sporozoites of Leucocytozoon caulleryi were inoculated into specific-pathogen-free (SPF) chickens intravenously. Fourteen days after inoculation, the infected blood, parasitized with second generation merozoites, was collected from the chickens. The blood was then suspended in SPF chicken serum or RPMI-1640 culture medium supplemented with 20% SPF chicken serum in petri dishes, which were cultured at 37 degrees C or 41 degrees C in a humidified atmosphere of 5% CO2. Second generation merozoites in parasitized, immature erythrocytes developed continuously through several substages and finally became micro- and macro-gametocytes after 6 days of incubation.     

Further characterization of the silkworm diapause hormone A

One of two diapause hormones (DH-A) was studied. DH-A was stable to acids, bases (except to 1·0 N NaOH), acylation agents and periodate oxidation. The hormonal activity was quickly lost by trypsin as well as by non-specific proteolytic enzymes but slowly or hardly at all by α-chymotrypsin and carboxypeptidase A. The hormone contains 14 kinds of amino acids and 2 kinds of amino sugars. The amino sugars appear not to be essential for the hormonal activity.     

Early schizonts of Leucocytozoon caulleryi

Sporozoites of Leucocytozoon caulleryi were inoculated intravenously into 26-day-old specific pathogen-free chickens. Six days after inoculation, early schizonts were detected in lung, spleen, and thymus. They existed separately and were spherical or ovoid, 30-35 microns in diameter, and had well defined walls.     

Effects of codon optimization and glycosylation on the high-level production of hydroxynitrile lyase from Chamberlinius hualienensis in Pichia pastoris

Journal of Industrial Microbiology & Biotechnology - A hydroxynitrile lyase (HNL) from the millipede Chamberlinius hualienensis has high potential for industrial use in the synthesis of...