The identity of the acid and alkaline phosphatases of human seminal plasma

Kavanagh, John P.; Bardsley, William G.

doi:10.1530/jrf.0.0570043

Cited by 19 publications

(8 citation statements)

References 15 publications

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“…Acid phosphatase (EC 3.1.3.2). This was prepared from human semen (Kavanagh & Bardsley, 1979) and was investigated with p-nitrophenyl phosphate (0.08-75 mM) as substrate and an enzyme concentration of 0.1,ug/ml. Over a large variety of experimental circumstances (pH, ionic strength etc.…”

Section: Methodsmentioning

confidence: 99%

Deviations from Michaelis-Menten kinetics. The possibility of complicated curves for simple kinetic schemes and the computer fitting of experimental data for acetylcholinesterase, acid phosphatase, adenosine deaminase, arylsulphatase, benzylamine oxidase, chymotrypsin, fumarase, galactose dehydrogenase, β-galactosidase, lactate dehydrogenase, peroxidase and xanthine oxidase

Bardsley¹,

Leff²,

Kavanagh³

et al. 1980

Biochemical Journal

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The possible graph shapes for one-site/two-state and substrate-modifier models are discussed. The two-state model is a version of the Monod-Wyman-Changeux model and gives a rate equation with 240 denominator terms. Discussion in terms of K and V effects is not possible. A simplified version of the mechanism can be shown to give v-versus-[S] curves that are either sigmoid or non-sigmoid. They may show substrate inhibition or no final maximum, and the double-reciprocal plots can be concave up or down. The corresponding binding model is determined by only two constants and gives a linear double-reciprocal plot. The substrate-modifier mechanism is a simple example of a mechanism where inclusion of catalytic steps leads to a genuine increase in degree of the rate equation. The v-versus-[S] curve can show such complexities as two maxima and a minimum, and the double-reciprocal plot can cross its asymptote twice, proving the rate equation to be 4:4. A simplified version is 3:3, and analysis shows that at least 18 of the 27 double-reciprocal plots that can arise with 3:3 functions are possible with this particular mechanism. Representative double-reciprocal and Scatchard plots are presented for several sets of rate-constant values. It is concluded that relatively simple mechanisms give pseudo-steady-state rate equations of high degree and considerable complexity. With extended ranges of substrate concentrations there is every reason to believe that experimental data would show the sort of deviations from Michaelis-Menten kinetics seen with calculated curves for such simple mechanisms. Narrow ranges of substrate concentration, on the other hand, would lead to inflexions and curvature being overlooked. It is not possible to discuss such deviations from Michaelis-Menten kinetics in terms of kinetic constants such as Km and V, and, in general, it is also difficult to see any simple way to explain intuitively such features as sigmoidicity, substrate inhibition, double-reciprocal convexity and decrease in degree by cancellation of common factors between numerator and denominator of rate equations. These conclusions apply with even more force when catalytic steps are included, for then the rate equations, are for multi-site mechanisms, of higher degree, allowing increasingly complex curve shapes. A number of enzymes were studied and initial-rate data were fitted by computer.(ABSTRACT TRUNCATED AT 400 WORDS)

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Section: Methodsmentioning

confidence: 99%

Deviations from Michaelis-Menten kinetics. The possibility of complicated curves for simple kinetic schemes and the computer fitting of experimental data for acetylcholinesterase, acid phosphatase, adenosine deaminase, arylsulphatase, benzylamine oxidase, chymotrypsin, fumarase, galactose dehydrogenase, β-galactosidase, lactate dehydrogenase, peroxidase and xanthine oxidase

Bardsley¹,

Leff²,

Kavanagh³

et al. 1980

Biochemical Journal

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“…Change in optical density per min was estimated at 405 nm at 37°C. Enzymatic activity has been expressed in International Units, which is defined as the amount required to metabolize 1 ~-tmol of substrate per min under the experimental condition (Kavanagh & Bardsley, 1979).…”

Section: Biochemical Analysesmentioning

confidence: 99%

Effect of tobacco consumption on the function of male accessory sex glands

Pakrashi

Chatterjee

1995

Int J of Andrology

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Summary The function of accessory sex glands in 29 tobacco smokers, 25 tobacco chewers and 30 non‐users of tobacco was investigated by determining the ejaculate contents of various glandular markers: N‐acetyl amino sugar and total phosphate (seminal vesicles) zinc and acid phosphatase (prostate gland), and α‐1,4‐glucosidase (epididymis). Both vesicular and prostatic parameters were reduced significantly in smokers compared with non‐users of tobacco, whereas these parameters were unchanged in tobacco chewers. This difference may be due either to the difference in constitution of xenobiotics emitted as a result of burning tobacco, or to differences in the pharmacokinetics of the two forms of tobacco consumption. The activity of α‐1,4‐glucosidase was significantly lowered in both types of tobacco users. It is concluded that use of tobacco, especially by smoking, impairs the secretory function of accessory sex glands in man.

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“…. , , _.. 1/4 ^ τ · j-' · ι η -j t. Λ The present investigation was concerned with the disammals (1)(2)(3)(4)(5)(6). It is secreted into seminal fluid by the ., .…”

mentioning

confidence: 99%

“…. ,,., j j " , c r\ Λ u +u * * tnbution of alkaline phosphatase activity in split ejacepididymis in rabbit and dog (5,6) and by the prostate , r , V ^i-ni-, 4 V "· /< o\ χ* Τ ι u-i * u · ulates of human semen, the response of this alkaline and testis in man (1,3 …”

mentioning

confidence: 99%

Alkaline Phosphatase in Human Semen: An Investigation Using Enzyme Inhibitors and Gel Electrophoresis

Lewin¹,

Golan²,

Soffer³

et al. 1993

Clinical Chemistry and Laboratory Medicine

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Summary: Human seminal alkaline phosphatase was investigated with respect to its electrophoretic mobility, heat lability, and susceptibility to inhibition by phenylalanine, tartrate, and homoarginine. Total alkaline phosphatase activity in 30 samples of human semen was measured colorimetrically, using /?-nitrophenylphosphate as substrate. Using linear regression analysis, no significant correlation was found between the enzyme activity and the sperm count, sperm motility, semen volume, and the concentrations of seminal inositol and fructose. The alkaline phosphatase activity was higher in the earlier portion of split ejaculate samples. Sodium DL-tartrate (42mmol/l), which inhibits acid phosphatase, did not inhibit seminal alkaline phosphatase significantly. L-Homoarginine (10 mmol/1), an inhibitor of the liver and bone isoenzymes, inhibited the seminal enzyme (53%), whereas L-phenylalanine (12 mmol/1), a strong inhibitor of placental alkaline phosphate, decraased activity by about 10%. Electrophoresis of semen samples on agarose revealed a braod band which was not sharpened after treatment with neuraminidase. Semen total alkaline phosphatase was essentially totally inactivated by heating at 56 °C for 15 min or 10 min at 65 °C; similar behaviour has been reported for the liver and bone isoenzymes. Electrophoresis after heating did not reveal a residual band of heat-stable placental-like alkaline phosphatase. Semen alkaline phosphatase appears to contain more than one isoenzyme, but placental-like alkaline phosphatase cannot be more than a minor component.

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The identity of the acid and alkaline phosphatases of human seminal plasma

Cited by 19 publications

References 15 publications

Effect of tobacco consumption on the function of male accessory sex glands

Alkaline Phosphatase in Human Semen: An Investigation Using Enzyme Inhibitors and Gel Electrophoresis

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