High impact information on AS-A

• All of these results designated a new function of AS-A in gamete interaction [1].
• In this report, we identified P68 as arylsulfatase A (AS-A) based on the presence of P68 tryptic peptide sequences in the pig testis AS-A cDNA sequence [1].
• The presence of AS-A on the sperm plasma membrane was conclusively demonstrated by indirect immunofluorescence, immunogold electron microscopy, and AS-A's desulfation activity on live mouse sperm [2].
• Furthermore, Alexa-430 conjugated AS-A bound to mouse ZP of unfertilized eggs but not to fertilized ones, and this level of binding increased and approached saturation with increasing Alexa-430 AS-A concentrations [2].
• Using anti-AS-A antibody, we have shown by immunoblotting that AS-A was present in a Triton X-100 extract of mouse sperm [2].

Biological context of AS-A

• Properties of arylsulfatase A, determined by hydrolysis of p-nitrocatechol sulfate, indicated that the enzyme was inhibited 46% by 3.1 microM Ag+ and had a pH optimum of 4 [3].

Anatomical context of AS-A

• When intact boar spermatozoa were incubated with arylsulfatase A, complete desulfation of seminolipid was observed [4].
• Arylsulfatase A was extracted and purified from boar epididymal sperm acrosomes [3].
• Arylsulfatase A was present in seminal plasma but not in extracellular fluids of the testis and epididymis nor in blood serum of boars [4].
• It appeared that the specific activity of arylsulfatase A was at least 20 times higher in the thyroid than in most other tissues [5].
• In conclusion, arylsulfatase A, a heterodimer of 120 kDa composed of two nonidentical subunits, is the major protein component of thyroid lysosomes [5].

Associations of AS-A with chemical compounds

• By fractionating intralysosomal soluble proteins by velocity sedimentation on sucrose gradients or gel permeation chromatography we identified a thyroid arylsulfatase A holoenzyme which corresponds to a 120,000 Mr species [5].
• An example of the latter is the removal of the sulfate group from cerebroside sulfate by arylsulfatase A. The mechanism of lipid sequestration from membranes and presentation of the lipid-protein complex to catabolic enzymes is a crucial aspect of the function of this protein [6].
• When compared to adrenal enzyme activities in animals on high dietary levels of ascorbate, the adrenals of animals on 2.4 mg of ascorbate per day expressed 50% increase in the activities of acid phosphatase, arylsulfatase A, and arylsulfatase B (p less than 0.02) [7].

Other interactions of AS-A

• Lysosomal enzymes, cathepsin D, beta-D-galactosidase, beta-D-glucosidase, alpha-D-mannosidase, alpha-L-fucosidase, hexosaminidase, and arylsulfatase A and B, were assayed in crude fractions from various pig tissues, heart, brain, liver, kidney, thyroid, adrenals, ovary, and spleen [5].

Analytical, diagnostic and therapeutic context of AS-A

• Immunogold electron microscopy revealed the presence of AS-A on the sperm surface [1].
• 1. Purification of arylsulfatase A was performed with a three-step procedure consisting of centrifugation (85,000 X g), affinity chromatography with p-aminobenzamidine-Sepharose followed by chromatography on diethyaminoethyl (DEAE) Sephadex [3].

References