Partial Purification and Characterization of Glycogen Phosphorylase from Dictyostelium discoideum

Author:

Jones Theodore H. D.1,Wright Barbara E.1

Affiliation:

1. Department of Developmental Biology, Boston Biomedical Research Institute, and Harvard Medical School, Boston, Massachusetts 02114

Abstract

Glycogen phosphorylase was isolated from cells of Dictyostelium discoideum in the culmination stage of development and purified 35-fold. The enzyme had a p H optimum of 6.9 and contained sulfhydryl groups essential for activity. The K m values for phosphate and glycogen were 3 m m and 0.06% (w/v), respectively. No dependence on, or stimulation by, any nucleotide was observed and a wide variety of nucleotides and glycolytic intermediates did not inhibit the enzyme. Nucleotide sugars competitively inhibited the enzyme. Guanosine diphosphoglucose and adenosine diphosphoglucose were the most effective, and uridine diphosphoglucose was the least effective of the nucleotide sugars tested. The specific activity of glycogen phosphorylase increased from about 0.004 unit per mg of protein in aggregating cells to about 0.024 unit per mg in culminating cells, and then decreased during sorocarp formation. This increase in enzyme specific activity during the starvation and aging of the system can account for the increased rate of glycogen degradation during this period of development. Amylase specific activity, measured at p H 4.8 and 6.9, varied between 0.005 and 0.013 unit per mg of protein during all stages of development.

Publisher

American Society for Microbiology

Subject

Molecular Biology,Microbiology

Reference28 articles.

1. Bernfeld P. 1955. Amylases a and p. 149-158. In S. P. Colowick and N. 0. Kaplan (ed.) Methods in enzymology vol. 1. Academic Press Inc. New York.

2. Brown D. H. and C. F. Cori. 1961. Animal and plant polysaccharide phosphorylases p. 207-228. In P. D. Boyer H. Lardy and K. Myrblck (ed.) The enzymes vol. 5. Academic Press Inc. New York.

3. Hormonal control of thyroid phosphorylase;Butcher F. R.;Biochim. Biophys. Acta,1968

4. Purification and properties of glycogen phosphorylase from Escherichia coli;Chen G. S.;Arch. Biochem. Biophys.,1968

5. Activities of glycolytic enzymes during the early stages of differentiation in the cellular slime mold;Cleland S. V.;Biochim. Biophys. Acta,1968

同舟云学术

1.学者识别学者识别

2.学术分析学术分析

3.人才评估人才评估

"同舟云学术"是以全球学者为主线,采集、加工和组织学术论文而形成的新型学术文献查询和分析系统,可以对全球学者进行文献检索和人才价值评估。用户可以通过关注某些学科领域的顶尖人物而持续追踪该领域的学科进展和研究前沿。经过近期的数据扩容,当前同舟云学术共收录了国内外主流学术期刊6万余种,收集的期刊论文及会议论文总量共计约1.5亿篇,并以每天添加12000余篇中外论文的速度递增。我们也可以为用户提供个性化、定制化的学者数据。欢迎来电咨询!咨询电话:010-8811{复制后删除}0370

www.globalauthorid.com

TOP

Copyright © 2019-2024 北京同舟云网络信息技术有限公司
京公网安备11010802033243号  京ICP备18003416号-3