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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

Proteoglycan as isolated from bovine nasal septa is a partially aggregated complex containing linking factors. Two essential factors can be separated from proteoglycan subunits and resolved in a CsCl density gradient. Chondroitinase digestion of the purified proteoglycan subunits does not interfere with their aggregation when the linking factors are added.

The presence of a sulfhydryl group in coenzyme A (CoA) has been established, in the form of ß-mercaptoethylamine linked through its amino group to the carboxyl group of pantothenic acid, as in pantetheine. The /3-mercaptoethylamine is liberated from CoA by an enzyme in pigeon or chicken liver. This is the only sulfur present in CoA, and by removal of impurities bound in a disulfide linkage, CoA has been obtained containing 25.6% pantothenic acid (about 90% pure).