A review of the work of the experimental farms, by J. B. Spencer.

Spencer, James

doi:10.5962/bhl.title.17733

Cited by 28 publications

(38 citation statements)

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“…The existence of many of these reactions has been inferred from the presence of sulfate conjugates in urine and secretions and from the study of detoxication mechanisms (64). Among those which have been observed in vivo or in tissue preparations are the sul furylation of many kinds of phenols (11,65,66,67), including triiodothyro nine (68) and tyrosine derivatives (69,70); of arylamines (71); steroids (72,73); mucopolysaccharides (11,74,75), heparin (76), and charonin (77); cerebrosides (78); and bilirubin (79).…”

Section: Sulfokinasesmentioning

confidence: 99%

Metabolism of Sulfur Compounds (Sulfate Metabolism)

Gregory¹,

Robbins²

1960

Annu. Rev. Biochem.

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SO much work has been published on sulfur compounds in the fourteen years since the last review in this series [Lugg (1)] that we have not attempted to cover the whole field. This paper is regretfully restricted to the metabo lism of sulfate, and many other areas must be slighted in which valuable developments have appeared. However, a few outstanding reviews and general works dealing with particular sulfur compounds should be mentioned: methionine (2), glutathione (3), lipoic acid (4), biotin and other compounds (5), protein sulfhydryl groups (6, 7), and a collection of papers in memory of C. Fromageot, including his complete bibliography (8). General reviews on sulfur metabolism have been published by Bersin (9), Young & Maw (10), and Dziewiatkowski (11).Although many good whole animal studies have appeared on the in corporation and distribution of sulfate [Dziewiatkowski (12)] and on the conjugation of phenolic compounds with sulfate, we shall report mainly en zymological work. Recent knowledge of enzyme reactions involving sulfate has been reviewed by Lipmann (13). The activation of sulfate to form a "high -energy" intermediate is the first step in its assimilation. Two paths are then open: the sulfate may be reduced, or it may be transferred. in which case the reaction is catalyzed by sulfokinases and various esters are formed. And finally, there are hydrolytic enzymes, the sulfatases, which split almost all sulfate esters. SULFATE ACTIVATIONDeMeio and his co-workers were the first to study phenyl sulfate forma tion in a ho mogenate (14). They showed that in a liver homogenate oxygen and mitochondria were necessary for phenyl sulfate synthesis and that ATP would replace these requirements (15). These workers were also among the first to show that the sulfate activating and -transferring systems could be separated (16). Bernstein & McGilvery (17) studied the conjugation of m aminophcnol in liver homogenatcs. By studying the kinetics of this system, they deduced that an intermediate activated sulfate was formed and that at least two enzymes were involved (18). They also showed that a com pound accumulated that would rapidly transfer sulfate when ATP, sulfate, 1 The survey of the literature pertaining to this review was concluded in September 1959.2 The following abbreviations are used in this review: AMP for adenosine mono phosphate; APS for adenosine-5'-phosphosulfate; p-NP and p-NPS for p-nitrophenol and its sulfate, respectively; PAP for 3'-phosphoadenosine-5 '-phosphate; PAPS for 3'-phosphoadenosine-5'-phosphosuJfate; PP for pyrophosphate; TPN+ and TPNH for oxidized and reduced tripho5phopyridine nucle otide, respectively. 347Annu. Rev. Biochem. 1960.29:347-364. Downloaded from www.annualreviews.org Access provided by Western Michigan University on 02/02/15. For personal use only.Quick links to online content Further ANNUAL REVIEWS

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Section: Sulfokinasesmentioning

confidence: 99%

Metabolism of Sulfur Compounds (Sulfate Metabolism)

Gregory¹,

Robbins²

1960

Annu. Rev. Biochem.

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“…Equation ͑6͒ should be valid at 433 K, but not at 623 K, where the effective deposition rate is low; at the higher temperature, ␤ Ϸ 100 would bring the full SVT model into agreement with experiment. 33 While these magnitudes of ␤ are not impossible ͑and indicate that Sn diffuses faster than Ge, which is expected given their respective melting points͒, we find that a 1.5% Sn film can have ␤ = 17, ␤ = 28, or ␤ = 87, solely as a function of substrate misfit. Although strain probably affects diffusivity, and may do so differently for different species, we cannot say whether the strain dependence predicted here is reasonable.…”

Section: Discussionmentioning

confidence: 53%

Kinetics governing phase separation of nanostructuredSnxGe1−xalloys

et al. 2006

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We have studied the dynamic phenomenon of Sn x Ge 1−x / Ge phase separation during deposition by molecular beam epitaxy on Ge͑001͒ substrates. Phase separation leads to the formation of direct band gap semiconductor nanowire arrays embedded in Ge oriented along the ͓001͔ growth direction. The effect of strain and composition on the periodicity were decoupled by growth on Ge͑001͒ and partially relaxed Si y Ge 1−y /Ge͑001͒ virtual substrates. The experimental results are compared with three linear instability models of strained film growth and find good agreement with only one of the models for phase separation during dynamic growth.

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“…The time evolution equation by surface diffusion of the lateral surface can be written as [1,5,6,8,17] dr Dy;QfSn " 2 ( , «el (2) with t the time, the surface Laplacian, Ds the surface diffusivity, n the atomic volume, SQ the number of atoms per unit area on the solid surface, k the Boltzmann's constant, and T the absolute temperature. The stress relaxation a,y with respect to the initial stress state < r® .…”

Section: Modelingmentioning

confidence: 99%