William N. Lipscomb

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTRecent Advances in Zinc EnzymologyWilliam N. Lipscomb and Norbert SträterView Author Information Department of Chemistry and Chemical Biology, Harvard University, 12 Oxford Street, Cambridge, Massachusetts 02138 Cite this: Chem. Rev. 1996, 96, 7, 2375–2434Publication Date (Web):November 7, 1996Publication History Received2 May 1996Revised25 July 1996Published online7 November 1996Published inissue 1 January 1996https://pubs.acs.org/doi/10.1021/cr950042jhttps://doi.org/10.1021/cr950042jresearch-articleACS PublicationsCopyright © 1996 American Chemical SocietyRequest reuse permissionsArticle Views5120Altmetric-Citations1184LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose SUBJECTS:Ions,Metals,Monomers,Peptides and proteins,Zinc Get e-Alerts

An LCAO—MO systematization of polyhedral molecules such as BNHN is undertaken. Peculiarities of polyhedral systems, such as inapplicability of nearest-neighbor assumption and increased number of parameters are discussed within the framework of a Hückel type of theory. It is found that inclusion of hydrogen atoms does not affect predictions of closed shells, but is important in determining electronic transitions. Various physical factorizations of the secular equations, such as the in-surface, apex-equatorial, and ring-polar separations are critically examined. A computer program for calculations on molecules of up to 15 atoms is described and used to obtain the energy levels of a variety of polyhedral molecules.

Abstract Numerous studies, both in enzymatic and nonenzymatic catalysis, have been undertaken to understand the way by which metal ions, especially zinc ions, promote the hydrolysis of phosphate ester and amide bonds. Hydrolases containing one metal ion in the active site, termed mononuclear metallohydrolases, such as carboxypeptidase. A and thermolysin were among the first enzymes to have their structures unraveled by X‐ray crystallography. In recent years an increasing number of metalloenzymes have been identified that use two or more adjacent metal ions in the catalysis of phosphoryl‐transfer reactions (R‐OPO 3 + R′‐OH → R′‐OPO 3 + R‐OH; in the case of the phosphatase reaction R′‐OH is a water molecule) and carbonyl‐transfer reactions, for example, in peptidases or other amidases. These dinuclear metalloenzymes catalyze a great variety of these reactions, including hydrolytic cleavage of phosphomono‐, ‐di‐ and ‐triester bonds, phosphoanhydride bonds as well as of peptide bonds or urea. In addition, the formation of the phosphodiester bond of RNA and DNA by polymerases is catalyzed by a two‐metal ion mechanism. A remarkable diversity is also seen in the structures of the active sites of these di‐ and trinuclear metalloenzymes, even for enzymes that catalyze very similar reactions. The determination of the structure of a substrate, product, stable intermediate, or a reaction coordinate analogue compound bound to an active or inactivated enzyme is a powerful approach to investigate mechanistic details of enzyme action. Such studies have been applied to several of the metalloenzymes reviewed in this article; together with many other biochemical studies they provide a growing body of information on how the two (or more) metal ions cooperate to achieve efficient catalysis.

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTCarboxypeptidase ADavid W. Christianson and William N. LipscombCite this: Acc. Chem. Res. 1989, 22, 2, 62–69Publication Date (Print):February 1, 1989Publication History Published online1 May 2002Published inissue 1 February 1989https://pubs.acs.org/doi/10.1021/ar00158a003https://doi.org/10.1021/ar00158a003research-articleACS PublicationsRequest reuse permissionsArticle Views2569Altmetric-Citations579LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InRedditEmail Other access optionsGet e-Alertsclose Get e-Alerts