Purification, crystallization and preliminary crystallographic analysis of the full-length cystathionine β-synthase from Apis mellifera.

Cystathionine β-synthase (CBS) is a pyridoxal-5'-phosphate-dependent enzyme that catalyzes the first step of the transsulfuration pathway, namely the condensation of serine with homocysteine to form cystathionine. Mutations in the CBS gene are the single most common cause of hereditary homocystinuria, a multisystemic disease affecting to various extents the vasculature, connective tissues and central nervous system. At present, the crystal structure of CBS from Drosophila melanogaster is the only available structure of the full-length enzyme.

Purification, crystallization and preliminary crystallographic analysis of human cystathionine β-synthase.

Human cystathionine β-synthase (CBS) is a pyridoxal-5'-phosphate-dependent hemeprotein, whose catalytic activity is regulated by S-adenosylmethionine. CBS catalyzes the β-replacement reaction of homocysteine (Hcy) with serine to yield cystathionine. CBS is a key regulator of plasma levels of the thrombogenic Hcy and deficiency in CBS is the single most common cause of homocystinuria, an inherited metabolic disorder of sulfur amino acids.

Ovulation rate and its relationship with follicle diameter and gene expression of the LH receptor (LHR) in Nelore cows.

The objective was to determine the relationship among the diameter of ovarian follicles, ovulation rate, and gene expression of the LH receptor (LHR) in Nelore cattle. In Experiment 1, ovulation was synchronized in 53 Nelore cows. Three days after ovulation, ovaries were assessed with ultrasonography, all cows were given 6.

[Hepatic disease associated with human immunodeficiency virus infection: anatomo-clinical study].

Objective: To study the spectrum of liver disease in the infection by the human immunodeficiency virus (HIV) and to assess the usefulness and indications of liver biopsy.

Patients: Fifty eight HIV seropositive patients (48 intravenous drugs users) were prospectively studied by means percutaneous liver biopsy, because of hepatic biological alterations, hepatomegaly or fever of unknown origin.

Results: Chronic hepatitis was the most common diagnosis, which was found in up to 20 patients (34%) (12 had chronic active hepatitis).