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SCHOLARLY
AND CREATIVE TEACHING
1957 - Research
technology, non-credit course, Dept. of histology and Embryology, 1958 - Sections of
Experimental Biochemistry, Dept. of Biochemistry, 1958 – 1962 - Sections of
Biological Chemistry, 1967 - 1969 - Biology
103-104, General Biology, Dept. of Biology, 1967 - 1969 - Biology 379,
1968 - 1969 - Biology 354,
Cellular Biochemistry, Dept. of Biology 1968 - 1969 - Biology 257,
Plant Physiology, Dept. of Biology, 990:494
Seminar in Zoology (1 cr) 115:413
Experimental Biochemistry (2 cr) 990:411
Endocrinology 115:414
Experimental Biochemistry (2cr) 990:204
Physiological Zoology (4 cr) 120:101 General
Biology Laboratory 115:310 Elementary
Biochemistry 115:312 Elementary Biochemistry 115:404 General
Biochemistry 760:407 General
Physiology 115:405 Problems in
Biochemistry 990:491 Special
Problems in Zoology Courses Taught (at 115:513 Metabolic
Pathways Controls (3 cr) 990:513 Metabolic
Pathways Controls (3 cr) 115:514 Metabolic
Pathways Mechanisms (3 cr) 990:514 Metabolic
Pathways Mechanisms (3 cr) 990:511 Advanced
Endocrinology (3 cr) 990:616 Special
Topics in Biochemistry (1 cr) 115:606 Advanced
Studies in Biochemistry 115:701 Research in
Zoology 990:509 Advanced
Problems in Zoology 160:572
Biochemistry Supervision of Honors
Thesis Completed by Students in the Undergraduate Honors Program: 1969
– 1968 - W.
Velez-Vega and M. Dieppa - Honors Program Advisor - 1981 - Nancee A. Novak -
The effect of cyclic nucleotides upon glycolysis in the human erythrocyte 1982 - Bessie B. Fouces -
Kinetic studies on brain adenylate cyclase 1984 - Sylvia Menendez -
The role of energy charge in the regulation of brain adenylate cyclase
activity Summer Supervision of 1982 Patricia Grady 1983 Patricia Grady 1984 James Anderson 1986 Manuel Dasilva VII. UNIVERSITY SERVICE 1967 – 1969 - Member of
the Graduate Faculty, Department of Biology, 1970 - Full member of the
graduate School of Rutgers University. 1970 - Full member of the cooperative
Graduate Program in Biochemistry, 1970 – 1973 - Member of
the University Science Council, 1975 - . Member of the
Academic Standards Committee of the Cooperative Graduate Program of
Biochemistry. 1970 - Member of several
graduate students’ committees in the Graduate Program in Biochemistry 1970 - Full member
Graduate Program in Zoology. NCAS 1970 - Member of several
graduate students committees in the
Graduate Program in 1975 – 1978 - Member of
the NCAS Academic Affairs Committee 1977 – 1978 - Member of 1979 – 1981 - Member of 1977 – 1978 - Member of
Curriculum Committee, Dept. of Zoology and 1978 - Member of Executive
Committee of the Graduate Program in 1979 - Member of Teaching
Evaluation Committee NCAS 1978 - Member , Cancer
Coordinating Committee of Rutgers, 1983, 1985 - Member, Executive Committee Graduate Program in 1984 – 1986 - Member of the advisory committee for MBRS program in
Newark Campus of Rutgers. VIII. GRADUATE STUDENT SUPERVISION Supervision of Ph.D. candidates
research and titles of Ph.D. dissertations completed by students under my direction and initial
post-doctoral positions: Susan B. Golz - Regulation
of brain adenylate cyclase by physiological and pharmacological factors. Ph.D. in Zoology awarded May 1976. Initial Position: Assistant
Professor, Robert H. Harris -
Hormonal regulation of rat fat cell CAMP levels and fat ceil membrane
adenylate cyclase. Ph.D. in
Biochemistry awarded November 1977. Initial Position: Research specialist,
Division of Metabolism of Food and Drug Administration, Heripsime Ohanian - The
role of divalent metals, adenosine 5'-triphosphate and hormones in the
regulation of rat brain adenylate cyclase.
Ph.D. in Zoology awarded June 1980.
Initial Position: Vincent A. DeBari -
Regulation of the hexose monophosphate pathway in cyclic nucleotides and
divalent cations in the human erythrocyte. Ph.D. in Zoology awarded May 1981.
Initial Position: Director, Renal
laboratory, Joseph W. Sulner - Renal
renin release - a stimulatory role for Calcium Ph.D. in Zoology awarded May
1984. Postdoctoral Hoffman – Laroche. Initial Position: Associate
Investigator N.Y. Veteran's Hospital. Rafaela Cruz - The
integration of hormones, Ng 2+ Ca2+ and their
nucleotide complexes on the regulation of brain adenylate cyclase. Ph.D. in
Zoology awarded October 1986. Initial
Position: Adjunct Faculty in Anatomy and Physiology at Pasquale Vicario – The
regulation of Insulin Receptor Tyrosine Kinase by Insulin, Divalent metal
cations and metal – ATP substrate. Ph. D. in Zoology awarded May 1988. Initial Position: Investigator at
Merck Company. Christopher Casciano – The
pharmacological characterization of the bicarbonate, proton, and mucus
transport systems of the rodent gastric mucosa and their significance in
cytoprotection. Ph. D. in Zoology awarded September 1988. Initial Position: Investigator at
Schering Company. Supervision of Ph.D. candidates research under my
direction: 1984 G. Serban 1985 P. Uychich 1985 L. Rumennick Supervision of Masters candidates research and Masters Thesis
completed by students: 1975 - Chairman of the
committee for the Master in Zoology of Susan Brydon Golz. M. Sc. awarded
1975. 1978 - Chairman of the
committee for the Master in Zoology of Heripsime Ohanian. M. Sc. awarded
1978. 1981 - Chairman of the
committee for the Master in Zoology of Rafaela Cruz. M. Sc. awarded 1981 Supervision of research: 1968 – 1969 - Advisor in
the Biology Program to 1. Bulla, M.S. candidate at 1970 – 1971 - Advisor in
the Graduate Program of Biochemistry to E. Albanese and V. Cannistraro. 1970 – 1971 - Advisor in
the Master in Zoology Sciences Program to E. Wallendjack 1977 - Research advisor to
Kamran Borhanian, student at NJCMD, 1977
- Postdoctoral research advisor to Salette de Farias
on a leave from Institute Butantan, 1984 - Research advisor to
Norbert Seidler, student at NJCMD, Membership on Graduate Student Committees: 1974 - Vincent Rama
(Ph.D., Zoology) 1977 - Jeff Stevens (M.S.,
Biochemistry) 1980 - Jeff Stevens
(Ph.D., Biochemistry) 1979 - Rosy Jordan (M.S., Zoology) 1979 - Gerald Costa (M.S.,
Zoology) 1980 - Robert Jonathan
Weiss (M.S., Zoology) 1980 - Beryl Joyce Carby
(M.S., Zoology) 1980 - Vera Minak (M.S.,
Zoology) 1980 - Frank R. Settineri
(M.S., Zoology) 1981 - Diane G. Verga (M.S., Zoology) 1983 - Dolores Curtis (M.S., Zoology) 1983 - Marlene Blanco (M.S., Zoology) 1983 - Mark Schachman
(M.S., Zoology) 1983 - Thomas Brankner
(M.S., Zoology) 1984 - Lee D. Carpe
(Ph.D., Zoology) 1984 - Dennis Guiliani
(Ph.D., Zoology) 1985 - Eva-Pia Reich
(Ph.D. Zoology) 1985 - Ilda D. D'Onofrio
(Ph.D. Zoology) 1988 - John C. Anthes (Ph.
D. Zoology) IX. RESEARCH ACCOMPLISHMENTS A. Active Transport and
metabolic control a) It was demonstrated that
active transport of phosphate by yeast is directly dependent on high levels
of energy – rich phosphates maintained by either endogenous oxidation or by
exogenous substrates during oxidation by either glycolysis or respiration. b) It was shown that yeast’s
uptale of acetate, pyruvate, etc. and their oxidation rate within the Krebs
cycle, rather than under direct control by oxygen itself, is subject to an
energy dependent regulatory mechanism supported by ATP levels and their
equilibria with other energy rich phosphate compounds. B. Mechanism of oxidative phosporylation In 1963, the DNP –
activated, Mg – dependent ATPase of yeast was for the first time isolated and
characterized for its role in oxidative phosporylation. III. Mechanisms of enzymatic induction and reversion as cells adaptative
response to environmental changes. It was found that
Wuglena controls endogenous phosphatase levels by a low phosphate contration
– dependent C. Mechanism of
photophosphorylation a)
In 1964, the proposition
that high energy intermediates should be equated with conformational changes
was published. It was proposed that conformational change participated in energy conservation and
transduction. Ca2+ and cysteine wiche eleicit light – requiring
ATPases were shown to, modify the kinetic behavior of the ATP synthetase. ADP
and GDP show inhibitory constants (Ki) for the light – requiring ATPases of
the same numerical value that their Kms for residual and modified
phtophosphorylation. This would suggest the participation of a single, but
modigiable, active center in the mechanism which would determine the
direction of the ATP synthetase activity b)
The first successful
resolution and reconstitution of an energy – dependent ATPase function was
achieved for chloroplast light – requiring ATPases. Isolation and
purification of the ATP-synthetase choroplast’s coupling factor. It was also
shown that the latter becomes an ATPase by heat or trypsin treatmen. c)
Reso1ution and
reconstitution of the functlon for metal-dependent binding of the coupllng factor
(ATP synthetase-ATPase) by the chloroplast membrane. Characterization of
allotopic properties of the system.
Characterization of the Inhibitory capacity by the membrane on the
ATPase activity during binding. d)
The finding of the
capability of the ATPase to maintain cooperative interaction with 2 ATP, 4PO4,
2 ADP and 16 molecules of water, was used to postulate that the active form
of the ATPase is a structure characterized by conserving the energy of 14
H-bonds or 14 Ki1oca1ories (1 kilocaloráe per each solvating water molecule),
where as that of the inhibited form of the ATPase is a estructure
characterized by a decrease in energy content of the same value. This appears
to indicate the potential of the ATPase itself to function as a high-energy
intermediate during the turnover of the ATP synthetase system. e)
First report on the
allosteric kinetics of the ATPase (activated coupllng factor), and
demonstration that proton concentration has the capability to requlate the
modification of the ATPase from a form of high affinity for ATP and low
affinity for phosphate and ADP, into another form of opposite properties. D.
Energy Transduction a)
Kinetic and thermodynamic
parameters were described for the operatien of ATPase coupled for ionic
transport, muscle contraction, interaction between cytochromes and coupling
factor (ATPase) and the effect of ions in the modification of chloroplast’s
light-dependent activities. b)
The postulation of energy
transduction mechanisms resulting from the exergonic association of proteins
with divalent metals (Me2+). The turnover of the protein te a
dissociated state (endergonic) is driven by the chelation of the binding Me2+
by ATP4- (exergonic). ATPase activiy turns ATP4- into
the waker chelating agent ADP3- allowing Me2+ dissociation
and the return te the initial high concentratien of free Me2+. c)
The binding of a divalent
meta1 requirement for the EDTA-treated membranes binding of the coupling
factor-ATpase led to the postulation that electron transfer is coupled to
phosphorylation by cytochreine-dependent or pH-dependent modificatien of the
meta1 chelated states of R-groups located in the coupling site of the ATPase. d)
Consequently, the unitary
hypothesis can be differentiated from the chemical hypothesis in that it
postulates the formation of high energy intermediates by the transfer of
groups across coordinative bonds rather than across covalent bonds. It also
integrates conformational and chemiosmotic prepositions within a single
framework. Accordingly, the hypothesis
uses a single thermodynamic and kinetic framework for findings that were
previously explained only through the alternate use of three different
hypothesis. E. Hemoglobin It has been previously proposed that in an
open thermodynamic system, the turnover of the state of Me2+ as
ligand of pretein(s) would yield the energy of activation for driving
conformational and functional changes of protein. Accordingly, it was proposed that
oxygenation of Hb would lead Me2+ induce-fit a chelating
configuration of side chains. This binding of Me2+ to Hb would
dislocate proxima1 histidines from the positions reguired for steric
hindrance and would allow Bohr side chanin(s) te release their
proton(s). Mg2+ rather than
Zn2+, was suggested as the main physiological Me2+ to
compete with Zn2+ at cellular concentrations of 11 ug/g red cells
for the chelating side-chains of Hb. Oxygenation induces binding of Mg2+
or Zn2+ to Hb. Hence,
according to the mode1 the PH-dependent stability order of the chelated
complexes during deoxygenation would be: (Zn2+)2-oxyHb>(Zn2+,
Mg2+)-oxyHb>(Mg2+)2-oxyHb F.
Characterization of the hormonal and metabolic parameters that control
adenylate cyclase activation a)
GH potentiates the effect
of epinephrine, glucagon and theophylline increasing endogeneus cAMP levels
in fat celis. b) Isolated membranes show that epinephrine activates adenylate cyclase
by decreasing its Km for ATP and its Km for Mg2+ to reach a
maximal activatory effect. Adenylate cyclase can be described as a
receptor-coupled enzyme system in where the hormone binding by the receptor
increases the affinity of the enzyme's regulatory site for Mg2+.
The regulatory site also functions in the absence of epinephrine because high
Mg2+ concentration is also capable of activating adenylate cyclase
(19) G.
Characterization of hormonal and metabolic parameters that desensitize and
inactivate adenylate cyclase a)
It was found that an
adenylate cyclase membrane preparation from rat's cerebral cortex, during
prolongued preincunation at b) Solving multiple-equilibirum equations demonstrated that the
relationship between energy charge (ATP vs. ADP and AMP) and relative
concentration of free vs. chelated by nucleotides divalent metals (Me: Mg2+,
Mn2+, Ca2+) plas a modulatory role for adenylate
cyclase and insulin-dependent tyrosine kinase at three sites (substrate site,
Me2+-dependet regulatory site and Me-requiring site for control of
hormone responsiveness) H. Metabolic controls The cellular uptake of
glucose and/or the lysis of glycogen it is expected to change the
concentrations of chelating metabolites (sugar phosphates) and therefore the
relative concentrations of free versus chelated divalent metals. Thus a decrease in chelating metabolites
constitutes an amplification mechanism of the adenylate cyclase (AC)
response, since it simultaneously increases the concentrations of the
substrate (MgATP) and the positive modulator (Mg +2) and decreases
that of the inhibitor (ATP 4-).
Mg2+ or Mn2+, in contrast with Ca2+,
may control not only the basal activity, but also the hormonal responsiveness
of AC. A more comprehensive description of metabolic shifts requires the
examination of hormonal action and metabolic feedback not only on AC, but
also on insulin receptor tyrosine kinase (IRTK). The metal dependence of IRTK, as well as
the effect of changes on chelated species of ATP on this dependence, were
investigated to elucidate the integrative parameters which allow coordinated hormonal,
ionic and energy-charge control of the metabolic shift from glycolysis to
gluconeogenesis. I. Control mechanisms for secretory processes: a) Renin release in kidney
tissue. b) HCl versus bicarbonate
in gastric tissue MAJOR
RESEARCH INTERESTS Metabolic Regulation: in yeast
Energy transduction: in chloroplast and mitochondrial membranes, resolution
and reconstitution, ATAase Control mechanisms of
enzyme-membrane systems: hormone receptors-adenylate cyclase systems in fat
cells and brain membranes, insulin receptor tyrosinekinases in liver. Modeling of Energy transduction
mechanism: Hemoglobin Areas of Specialization -
Cellular actions of hormones Enzyme kinetics Cellular structure and function
Membrane biochemistry of organelles, chloroplasts and mitochondria |
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