Hernan Chaimovich | Universidade de São Paulo (original) (raw)

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Papers by Hernan Chaimovich

Journal of the Brazilian Chemical Society, 2023

Revista USP, Dec 22, 2022

Biochemical Society Transactions, Oct 1, 2000

Estudos Avançados, Dec 1, 2000

Biochimica Et Biophysica Acta - Proteins And Proteomics, Jun 1, 1973

Chemistry and Physics of Lipids, Feb 1, 1976

Estudos Avançados, Dec 1, 2005

Journal of Physical Chemistry A, Jun 1, 2005

Iubmb Life, 2008

Background: Born in Chile in 1939, my childhood was deeply influenced by the Second World War, th... more Background: Born in Chile in 1939, my childhood was deeply influenced by the Second World War, the Holocaust, the ideologies that flourished at the time, the proclamation of the State of Israel, and the beginning of the Cold War. Chile, a country where the mountains and the sea are permanent references, induces decisions based on firm and clear landmarks. My family was large and passionate. One grandfather, an intellectual and conservative Jew, ran from the communists after 1922. He was never fully at ease with Chilean society; with him the themes were religion and world politics. My other grandfather left Russia before the First World War and was as integrated in Chilean society as his Spanish pronunciation permitted. He was always ready for good scotch and friendly gossip. Of course my grandfathers did not like each other. My father was a pharmaceutical chemist that enjoyed life with a superlative enthusiasm. My mother, a devotee of all things literary and a Master Chef, later became a writer. One of her last novel’s title, ‘‘Para Siempre en mi Memoria’’ (1), could represent these reminiscences. One of my uncles, a physician that did some clinical research, was an accomplished dancer and piano player and knew everything about nightclubs. Mother’s sister was a communist until her premature death. Saturday family lunches at my parents’ home were lively events, with superb food and exciting political debates. Family influences, contradictory as they were, accustomed me to see various interpretations of single events and introduced me to dialectics. The end of the family lunches, with the advent of the Pinochet’s dictatorship, reflected the roots of the divide in Chilean society, some of which remain to this day. School: I learned to read and write in English in a private school and completed my education in the Instituto Nacional (Instituto), a public institution where many Chilean leaders have studied over almost two centuries. In high school I was busy partying, dating, skiing, and reading and did not study much, except Chemistry, Biology, Physics, and Philosophy. At the Instituto, we began to learn the theory and practice of politics, which I have been involved in since. In my father’s pharmaceutical laboratory I had my first contact with Chemistry. One of the lab consultants gave me chemistry books for children as birthday gifts, so I started experiments very early. Some experiments did not go as planned, and I almost destroyed the family garage. A microscope, fermented leftovers, and garden bugs introduced me to hands-on Biology. With my mother’s advice, I read ‘‘the Russians’’ and a number of the classics before I left school. Dr. Arrowsmith was not read without consequences and, never modest, I dreamed on saving humanity through Chemistry and Biology. University as an undergraduate: At age 17, I was admitted to the Facultad de Farmacia of the Universidad de Chile (FF/ UCh) to study Pharmacy. During the first semester, I had to stay in bed for almost one month. The social worker that visited me at the end of the rest period advised me to study only one or two disciplines that year. Not liking the idea, I passed all exams and won some prizes as the best student in my class. Taking (some of) the courses seriously made me interested in the basic aspects of Science. The pharmaceutical parts, and my father’s lab for the matter, were not attractive for me. At the Address correspondence to: Hernan Chaimovich, Instituto de Quı́mica, Universidade de São Paulo, São Paulo, SP, Brazil. Tel: 155 (11) 3091 2177. Fax: 155 (11) 3091 3839. E-mail: hchaimo@usp.br Received 23 July 2007; accepted 24 July 2007

General Pharmacology-the Vascular System, Aug 1, 1976

Biochimie, Sep 1, 1997

Limited proteolysis of fatty acid-free bovine serum albumin by pepsin yields several well charact... more Limited proteolysis of fatty acid-free bovine serum albumin by pepsin yields several well characterized peptides, one of which (P9, M(r) 9,000), induces fusion of small unilamellar vesicles (SUV) of phosphatidylcholine at pH 3.6. Circular dichroism (CD) of P9 solutions confirmed that the peptide undergoes a reversible transition between pH 7 and pH 3.6. The spectral changes observed with CD suggest that in the low pH conformation there is a decrease in the alpha-helical contents and an exposure of hydrophobic residues. CD and differential ultraviolet spectroscopy demonstrated that P9 binds to micelles of hexadecylphosphorylcholine and the binding produces changes in the tertiary structure of the peptide. Reduction and carboxymethylation of the two disulfide bridges of P9 produced loss of the ability to induce fusion of SUV, although the reduced peptide binds to vesicles, induces loss of entrapped marker and produces vesicle disruption. In the active form P9 exposes hydrophobic groups, one amphiphilic alpha-helix and requires the integrity of the disulfide bridge-stabilized tertiary structure.

Journal of Pharmacy and Pharmacology, Oct 1, 1993

Journal of Pharmaceutical Sciences, May 1, 1997

Two amphiphilic oximes, 10-phenyl-10-hydroxyiminodecanoic acid (oxime 11) and 4-(9-carboxynonanyl... more Two amphiphilic oximes, 10-phenyl-10-hydroxyiminodecanoic acid (oxime 11) and 4-(9-carboxynonanyl)-l-(9-carhoxy-1-hydroxyimino nonany1)benzene (oxime 111) were synthesized. The pK. values of oximes I1 and I11 and acetophenoxime (oxime I) and the rates of oximolysis of p-nitrophenyl acetate (NPA) and p-nitrophenyl octanoate (NPO) were determined in the presence and absence of micellar hexadecyltrimethylammonium bromide (CTAB). The rates of oximolysis increased by up to 3 x 104-fold in the presence of CTAB. Quantitative analysis of micellar effects, using an ion-exchange pseudo-phase model, allowed the determination of the second-order rate constants for the reactions of oximes 1-111 with NPA and NPO in the micellar pseudo-phase. The calculated rate constants in the micellar pseudo-phase were lower than those in water, demonstrating that the rate enhancements were due to substrate concentration in the micelles. Comparison of the rate constants in micelles and water suggests that the sites of reaction of oximes 1-111 with NPO and NPA are similar to those in hulk aqueous solution. Micellar incorporation of the hydrophobic oximes I1 and I11 does not lead to a major change in the nucleophilicity of the oximate anion.

Langmuir, May 1, 1995

... tration of the additive (Figure 1). These results are presented in a quantitative form in ...... more ... tration of the additive (Figure 1). These results are presented in a quantitative form in ... A directcomparison of the effect of urea on the limiting area per head group (A ... monolayer compression isotherms (pres-sure (P) versus area per monomer (A)) for differnt urea concentrations in ...

Estudos Avançados, 2022

RESUMO A Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), do ponto de vista de quem... more RESUMO A Fundação de Amparo à Pesquisa do Estado de São Paulo (Fapesp), do ponto de vista de quem chegou ao Brasil com bolsa e auxílio da Fapesp. Durante quinze anos, em posições funcionais, passa a conhecer a Fapesp por dentro. Descrevem-se as bases constitucionais, federais e estaduais, bem como os elementos infraconstitucionais que permitem à Fapesp ser uma das Agências de apoio à pesquisa mais distinguidas do mundo. O artigo descreve a mecânica de avaliação de projetos e programas. Os resultados dos investimentos da Fapesp em pesquisa científica produzem impactos intelectuais, econômicos e sociais em benefício do contribuinte paulista. Contudo, o patrimônio e o orçamento da fundação têm sido ameaçados repetidamente. Finalizando, o texto afirma que a manutenção da identidade da Fapesp requer o apoio de toda a sociedade paulista, pois a promoção da ciência e tecnologia traz benefícios que em muito excedem os seus investimentos.