In hemoglobin Richmond (beta102 leads to Lys), amino acid substitution has occurred at the same site as the mutation in hemoglobin Kansas (beta102 Asn leads to Thr), a variant with very low oxygen affinity. Although hemoglobin Richmond has been shown to have increased tetramer-dimer dissociation, its oxygen affinity has been inferred to be normal from studies on hemolysates of carriers. We have...

Pulmonate snails that experience extreme variations in gas tensions and temperatures possess extracellular, high-molecular mass (∼1.7 × 106 Da) hemoglobins (Hbs) that are little known as regards oxygenation and allosteric characteristics. Biomphalaria glabrata hemolymph exhibits a high O2 affinity (half-saturation O2 tension = 6.1 mmHg; pH 7.7, 25°C), pronounced Bohr effect (Bohr factor = -0.5)...

introduction: the major histocompatibility complex (mhc) is a group of cell surface proteins that are essential for recognizing foreign molecules in human and other mammals. the physiologic function of mhc molecules is the presentation of peptides to t cells. in this study, we evaluated the purification of a class ii mhc molecule (hla-dr) from a human burkitt′s lymphoma cell line; daudi. materi...

Aromatic rings form energetically favorable interactions with many polar groups in chemical and biological systems. Recent molecular studies have shown that sulfonamides can chelate metal ions hydrogen bonds, however, it is presently not established whether the sulfonamide functionality also interacts aromatic rings. Here, synthetic, spectroscopic, structural, quantum analyses on 2,6-diarylbenz...

In recent years we have seen an important increase in the number of protonated molecules detected cold dense clouds. Here report detection TMC-1 HCCNCH+, form HCCNC, which is a metastable isomer HC3N. This first cloud. The was based on observations carried out with Yebes 40m and IRAM 30m telescopes, revealed four harmonically related lines. We derive rotational constant B = 4664.431891 +/- 0.00...